The complaint can be filed within 2 years of cause of action. You can collect all the evidences first through RTI about exact time for arrival / departure, actual time on that particular day of those trains, total delay of those trains.
It can not be certain that you will receive compensation, and it depends on circumstances / facts of the case, whether it is reasonable or unreasonable.
There is a process of recording time on your ticket by Railways. Have you obtained such confirmation ?