Partition by memondrum

My grandfather were four brother,they don't have any ancestral property,later,in1945$1949,two of them purchased Aland,in joint name . A ,.b ,in meen time a mygrandfather started milling business with3 other partner with registered deed from1945onwards,letter that partnershipbussness came to end, all the assets$land came in hand of my grandfather by registered sell deed,in meen time a$b both took many land in there name by sellers,in there own name respectively .while that time they sold land respectively to other person,also,in1983my grandfather by bank taken loan with his 2son$paid letter,in milling business,in that time.after mygrandfather,nephew asking 1/2share in mill proproty which was in my grand father name,tellig that we were also in that business,&telling a memondrom date1986that half share to nephew ,half to his son,memondrum is 16rs stamped duaily signed but signed is furged it seem can a nephew have will have1/2share in my grand father milling business land which was in his name alone?