1. Contact Adv Ajay Sethi expert of this site who practices at Mumbai,
2. partition suit takes very longtime,
3. Must file application under Order 39 Rule 1 & 2 praying for an order restraining your brother in creating any third party interest on the said flat till the disposal of the partition suit as suggested in my earlier post,
4. Since the partition suit will run for around 2 years and your brother will not be able to sell the same till then, he will come out for a settlement with you which you may accept at that time.