Procenitelj će proceniti štetu pod uslovom da je dokumentacija spremna.

They come from the same root, procen-, which is related to estimating or assessing.

• proceniti = to assess / to estimate
• procenitelj = the person who assesses

The ending -itelj is a common way to form a noun meaning the person who does the action.

This is the Serbian Future I tense.

It is often formed with:

• a short form of hteti (ću, ćeš, će, ćemo, ćete, će)
• plus the infinitive

So:

• će proceniti = will assess

You may also see the fused form:

• proceniće

Both mean the same thing. In this sentence, će proceniti is perfectly standard.

Proceniti is a perfective verb. That means it presents the action as a completed whole: a finished assessment.

That fits this sentence well, because the idea is that the appraiser will carry out and complete the assessment once the condition is met.

The imperfective partner would be something like procenjivati, which would focus more on the process, repetition, or ongoing action.

Because štetu is the accusative singular form of šteta.

• šteta = nominative, the basic dictionary form
• štetu = accusative, used here because it is the direct object of proceniti

The appraiser is assessing the damage, so damage is the thing being acted on.

Pod uslovom da means provided that, on condition that, or as long as.

It is similar to ako (if), but it sounds more formal and more explicit about a condition that must be met.

So:

• ako je dokumentacija spremna = if the documentation is ready
• pod uslovom da je dokumentacija spremna = provided that the documentation is ready

In your sentence, pod uslovom da is a good choice because it sounds official and conditional.

Here, je is simply the present tense of biti (to be), third person singular: is.

So:

• dokumentacija je spremna = the documentation is ready

After pod uslovom da, the clause is:

• da je dokumentacija spremna = that the documentation is ready

So in this sentence, je is not part of a past tense construction. It just means is.

Because it agrees with dokumentacija, which is a feminine singular noun.

In Serbian, adjectives must agree with the noun in:

• gender
• number
• case

So:

• dokumentacija is feminine singular
• therefore the adjective must be spremna

If the noun were masculine, you would get spreman. If it were neuter, spremno.

Usually no. Dokumentacija generally means documentation, paperwork, or the set of required documents as a whole.

It is grammatically singular, but semantically it often refers to multiple documents.

So dokumentacija je spremna means something like:

• the paperwork is ready
• the documentation is ready
• all the required documents are prepared

Because Serbian does not have articles.

English uses:

• a/an
• the

Serbian usually leaves this unspecified and lets context show the meaning.

So procenitelj can mean:

• an appraiser
• the appraiser

And štetu can mean:

• damage
• the damage

In this sentence, English translation usually uses the because the context makes the reference specific.

Serbian word order is fairly flexible.

The given sentence is natural:

• Procenitelj će proceniti štetu pod uslovom da je dokumentacija spremna.

But you could also say:

• Pod uslovom da je dokumentacija spremna, procenitelj će proceniti štetu.

That puts more focus on the condition first.

Even with flexible word order, clitics like će have placement rules, so not every rearrangement sounds equally natural. But overall, Serbian allows more movement than English does.