Teslim için gereken evraklar masada.

Because Turkish often leaves out the present-tense form of to be in sentences like this.

So:

• Teslim için gereken evraklar masada. = The documents required for delivery are on the table.

Here, masada is the predicate, and the meaning of are is understood automatically.

This is very common in Turkish:

• Kitap masada. = The book is on the table.
• Çocuklar okulda. = The children are at school.

If you wanted a different tense, Turkish would show it more explicitly:

• Evraklar masadaydı. = The documents were on the table.

İçin is a postposition that usually means for.

So:

• teslim = delivery / submission / handover depending on context
• teslim için = for delivery / for submission

In Turkish, için comes after the noun, not before it like English for.

Compare:

• sınav için = for the exam
• iş için = for work
• teslim için = for delivery / for submission

So the phrase teslim için gereken evraklar means the documents needed for delivery/submission.

Gereken means needed, required, or more literally that is necessary.

It comes from gerekmek, which means to be necessary.
The ending -en / -an can turn a verb into a participle that describes a noun.

So:

• gerekmek = to be necessary
• gereken = necessary / needed / required

Then:

• gereken evraklar = the documents that are needed
• more naturally in English: the required documents

This is a very common Turkish pattern:

• gelen adam = the man who came
• bekleyen insanlar = the people who are waiting
• gereken evraklar = the documents that are required

Because in Turkish, descriptive words and phrases usually come before the noun they modify.

So Turkish builds the noun phrase like this:

• teslim için = for delivery
• gereken = needed
• evraklar = documents

Put together:

• teslim için gereken evraklar = the documents needed for delivery

English often puts longer modifiers after the noun, but Turkish puts them before it.

That is why Turkish says something closer to:

• for-delivery needed documents

rather than:

• documents needed for delivery

Because evraklar is the basic plural form: documents.

In this sentence, evraklar is the subject, so it stays in its plain form.

• evraklar = documents

But evrakları would usually mean something else, such as:

1. the documents as a definite direct object

   • Evrakları getirdim. = I brought the documents.

2. or a possessed form depending on context

   • onun evrakları = his/her documents

So in Teslim için gereken evraklar masada, the plain subject form evraklar is the correct choice.

Masada is:

• masa = table
• -da = locative ending, meaning something like in / on / at

So masada literally means at the table / on the table / in the table-area, depending on context.

In this sentence, with documents, English naturally says on the table.

This is important: Turkish does not always match English prepositions one-for-one.
The locative ending -da / -de / -ta / -te can cover meanings that English expresses with in, on, or at.

Examples:

• evde = at home / in the house
• okulda = at school
• masada = on the table / at the table

It is the locative case ending.

The locative has four common forms:

• -da
• -de
• -ta
• -te

The form changes because of vowel harmony and consonant harmony.

Here:

• masa ends in the vowel a
• so the vowel in the suffix becomes a
• and since there is no voiceless consonant forcing a change to t, the suffix is -da

So:

• masa + da = masada

Compare:

• ev + de = evde
• okul + da = okulda
• park + ta = parkta

Because Turkish does not need to mark plural on the predicate when the subject is already clearly plural.

So:

• evraklar masada = the documents are on the table

This is completely normal.

Turkish often does this with third-person plural subjects:

• Öğrenciler sınıfta. = The students are in the classroom.
• Kitaplar rafta. = The books are on the shelf.

A form like masadalar can exist, but with a noun subject it is less neutral and often unnecessary.
The simple version evraklar masada is the most natural here.

Yes. Teslim için gerekli evraklar masada is also correct and natural.

The difference is small:

• gerekli = necessary / required as an adjective
• gereken = needed / required, more like that is required

So:

• gerekli evraklar = necessary/required documents
• gereken evraklar = the documents that are needed

In many everyday situations, they are very close in meaning.
Gereken can sound a little more specific or contextual, while gerekli can sound a bit more like a dictionary adjective.

Yes, Turkish word order is flexible, although the version you have is very natural.

• Teslim için gereken evraklar masada.

This puts the location masada at the end, which often sounds like the new or important information.

You could also say:

• Masada teslim için gereken evraklar.

but that sounds less neutral by itself and may feel more marked or contextual.

The original sentence is a very normal way to say:

• The documents required for delivery are on the table.

So even though Turkish allows movement for emphasis, the given order is a good standard pattern.

This is a good question because evrak can behave a little differently from a simple count noun.

In modern Turkish:

• evrak often means paperwork / documents as a collective noun
• evraklar can still be used when you want to emphasize separate documents or speak more concretely about them

So both can occur, but they are not always used in exactly the same way.

For example:

• Evrak lazım. = Paperwork/Documents are needed.
• Evraklar masada. = The documents are on the table.

In your sentence, evraklar sounds perfectly natural because the speaker has a specific set of documents in mind.