How long will it take to put a person in prison after i report?

A guy from my native has been disturbing me through phone calls/messages for the past 6 years. At the beginning, he was calling me one/twice a year and hence i ignored. But after 3 years(from 2015), he started calling me more frequently and tried to have a conversation with me even though I made it very clear so many times that I do not or did not have any interest in him. I have changed my ohoen numbers twice. Of late, he has been sending facebook messages to me from many of his accounts and these messages contain obscene language and its frightening sometimes. He is also sending senseless messages to my office email as well(to the office support email address that is given in office website). Because of this, I feel like I am losing respect in my office too. I have already submitted all the proofs and filed a charge sheet in a Women police station, Pollachi. The Sub-Inspector of police made a conversation with him over phone and he said he will not disturb again. But he still continues to do the same kind of activities(even on higher extent) and he is doing this only on purpose of spoiling my name and career. I am scared to take it further by registering an FIR. Because i have following questions running in my head. Can he get bail immediately after i file FIR? how long it will take to punish him? how often do I have to go to court?