Hi please help me my sister marriage was fixed with a guy so engagement was conducted before marriage but after engagement that guys father is demanding dowry and is black mailing us that he will cancel this marriage if demanded dowry is not paid . We have spent a lot on engagement and we are not in a position to give him any more dowry so please help me can I lodge a complaint against him can I get them punshised for their acts I have a video of engagement please help me

You can demand only 50% of the cost you spent for engagement. Why do you want to complain about it, as after complaint do you think they will come back and the boy marries your sister? Will they be peaceful after marriage once they go through this situation? Do not try to threaten people just by taking law in to hands. Try to be peaceful and let others be at peace.