Alimony and Maintenance in Hindu Divorce

My parents recently agreed for a mutual consent divorce. Father agreed to pay only Rs 1,50,000 permanent alimony (has property and savings worth much much much more, but refused to give divorce under any other condition). My mother was not in a financial position to hire a lawyer and file normal divorce case so she unwillingly accepted to get rid of him (father was very violent). Now she doesn't want to go through the divorce under mutual consent as the amount is too low to sustain a standard of living and support my education. Father has also refused to pay for my education citing that he is not legally bound to pay for it once I am 18+. Now coming to the main point, mother has already received Rs 50,000 alimony (out of Rs 1,50,000) in advance. If she decided to not go through the process, will she have to repay that Rs 50,000? Any guidance is highly appreciated