West bengal premises tenancy act

Our present residence is rented one since last 44 years, tenancy was in my father name, after his death in february 2013 rent receipt was issued in the name of my brother on the written request of all other legal hires. original landlord sold the building to the promoter,promoter also issued 19 months rent receipt in the name of brother now new owner/promoter has given eviction notice on the ground that since original tenant is deceased, u all have to vacate the flat in a period of 5 years from the death of original tenant. again ne landlord/ building owner is carrying on the business of construction & sale of flat, he buy old building with tenant, after that does the reconstruction on the land and sales flat, we have the copy of such sale deed new building owner in his eviction notice has also demanded eviction on the ground " reasonably required for own residence and business: please advise to us / tenant our legal status, will landlord / building owner will succeed in his eviction case sushil saraf tenant Email: SARAFATMARAM@GMAIL.COM