If the movie already has subtitles
Select that track and translate its text. Existing timestamps remain attached to the dialogue.
If you have an external SRT
Confirm that it matches the exact movie release, then open it with the movie and translate it.
If there are no subtitles
Generate subtitle text from audio locally, review it, and translate the text if the spoken language differs from your target language.
If timing is wrong
Use a global delay for a consistent offset. If timing drifts, the SRT may belong to a different cut and should be replaced or retimed in an editor.