i want to cancell my ticket
Once the seats get allotted by IRCTC there is no way to get your seats changed. The Seat allocation is done by IRCTC and it depends upon many factors like reservation quotas, location quota, seat availability, etc. You can ask co-passengers to exchange the seat with you. They will definitely understand the situation and will exchange berth. Still, if there is some issue you can contact TTE and explain the situation.