Property Dispute Among Brother

I and my brother had bought a room 20 years ago together by giving a 50-50 amount at that time but unfortunately, my brother made all the documents on his name. I and my family is staying in that room from the past 20 years. Now he is claiming that this room had bought by him and I have not given any money. We had a mutual discussion with few people including my brother and came to the decision that he will give me 6 Lakh rupees for that room. This deal was written on a 100 rupees stamp paper with few people and my brother signature agreeing on this amount to be paid within 1 year now it's been 6 months and he is not ready to give a single penny. We are totally helpless left with nothing. Please guide me on this.