When you go to the police station to file a complaint, the details of the complaint will be written down in an FIR (First Information Report).
The FIR has to be filed by the police official and if you are a woman or trans woman, then for certain crimes, a woman police officer has to fill out the FIR.
Before filing the FIR, consult with a lawyer and see what all crimes you can file an FIR for as some crimes can only be reported by women or trans women and not men. If you face any difficulties while filing an FIR, read here to see what steps you can take.
Read here to understand what happens after you file the FIR.