Registering sale based on unregistered koor-chit

I have a property which was bought jointly with 5 co-workers. We wrote a memorandum of partition (Koor-Chit) later on to demarcate each person's share. But before we registered this, one person died. Land was low value. So we didn't bother any further. But now, I need to sell my share of it despite unregistered Koor-Chit. One of the 6 persons, was able to sell his plot showing only the unregistered Koor-Chit. So it is possible. This is in Chennai. Anyone on here familiar how to do this? Can carry out the work?