Southern Railway — Misbehavior of a copassenger

I was travelling from new delhi to chennai via tamil nadu express on the 8.8.2016 in a2-34. The only other copassenger in my cabin was a man on seat 33. He was dressed in complete white attire and must have been in his 70's. We spoke briefly and then went to bed after the tte checked our tickets. Late in the night i caught this man touching me from his berth. I shouted at him thrice, and even caught him red handed while he pretended to sleep. I was terrified and used my bag as a shield and lay inwards. When the tte came after the bhopal junction stop. I got down and told him the entire incident and asked for a change in seat. The remaining journey was very disturbed. I have always preferred train journeys but this journey has scared me. I hope this matter is looked into seriously so no one has to go through this.