ऑफिस के बाद हम ट्रेन का टिकट खरीदेंगे।

के बाद means after. Hindi uses postpositions, which come after the noun, unlike English prepositions.

So:

• ऑफिस = office
• के बाद = after

Together, ऑफिस के बाद means after office or, more naturally in context, after work / after office hours.

It is best to learn X के बाद as a very common pattern meaning after X.

Because Hindi normally needs the full postpositional expression के बाद.

You cannot usually drop के here. The pattern is:

noun + के बाद = after noun

Examples:

• खाने के बाद = after eating / after the meal
• स्कूल के बाद = after school
• काम के बाद = after work

So ऑफिस के बाद is the normal form.

Many learners notice that some Hindi nouns change before postpositions, but ऑफिस does not.

That is because only certain nouns change form in the oblique case. A very common pattern is:

• लड़का → लड़के
• कमरा → कमरे

But nouns like ऑफिस, which do not end in -ा, usually stay the same in the singular:

• ऑफिस
• ऑफिस के बाद

So this is completely normal.

Because Hindi usually follows Subject–Object–Verb word order.

Here the sentence is:

• हम = we
• ट्रेन का टिकट = train ticket
• खरीदेंगे = will buy

So the structure is:

After office, we train ticket will buy.

That sounds strange in English, but it is normal in Hindi.

Literally, it is something like the train’s ticket, but that is not the best natural English translation.

In real usage, ट्रेन का टिकट means:

• a train ticket
• the ticket for the train

Hindi often uses का/की/के to connect two nouns like this. So this is a very common way to say ticket for a train.

Because का/की/के agrees with the following noun here, and टिकट is treated as masculine singular.

So:

• masculine singular → का
• feminine singular → की
• plural / some other contexts → के

Since टिकट is masculine singular, का is correct:

• ट्रेन का टिकट

A useful comparison:

• ट्रेन का टिकट = train ticket
• ट्रेन की सीट = train seat

Here सीट is treated as feminine, so की is used.

Hindi does not have articles like a, an, and the the way English does.

So टिकट can mean:

• a ticket
• the ticket
• just ticket

The exact meaning depends on context. In this sentence, English will usually translate it as a train ticket, unless the conversation already makes a specific ticket clear.

खरीदेंगे is the future form of खरीदना (to buy).

With हम (we), the future ending is -ेंगे:

• हम खरीदेंगे = we will buy

That -ेंगे ending is also commonly seen with:

• वे = they
• आप = you (polite)

So the verb itself tells you that the action is in the future.

Because ने is not normally used in simple future sentences like this.

You often see ने in many perfective past sentences, for example:

• हमने टिकट खरीदा = we bought a ticket

But in the future:

• हम टिकट खरीदेंगे = we will buy a ticket

So हम खरीदेंगे is correct, and हमने खरीदेंगे would be wrong.

It is a very common loanword from English, written in Devanagari as ऑफिस.

Modern Hindi uses many borrowed everyday words, especially for work, transport, technology, and city life.

A more traditional Hindi/Urdu word is दफ़्तर:

• दफ़्तर के बाद = after office / after work

Both are understandable, but ऑफिस is extremely common in everyday speech.

It can absolutely mean after work.

In everyday Hindi, expressions with places often refer to the time or activity connected with that place, not only the physical location. So ऑफिस के बाद very often means:

• after work
• after office hours
• once we’re done at the office

Context decides the exact nuance.

A simple pronunciation guide is:

ofis ke baad hum ṭren ka ṭikaṭ kharīdenge

A few notes:

• ऑफिस ≈ office
• ट्रेन ≈ train
• टिकट ≈ ṭi-kaṭ
• खरीदेंगे ≈ kha-REE-den-gey

If you want to sound more natural, keep the rhythm smooth and let the verb खरीदेंगे carry the main sentence ending.

Yes. A couple of natural alternatives are:

• दफ़्तर के बाद हम ट्रेन का टिकट खरीदेंगे।
  Same meaning, but using दफ़्तर instead of ऑफिस.

• ऑफिस के बाद हम ट्रेन का टिकट लेंगे।
  This literally means we will take/get the train ticket, but in everyday Hindi it can also sound natural for we will get/buy the train ticket.

So the original sentence is correct, but there are other natural ways to express the same idea.