house rent

Hello sir, my father lived in 2 room with common bath in kolkata for last 40 yrs. No rent contract was signed then, after death of landlord his wife sing on rent receipt but she expired on jan 2014. His 7 son and family are living with same premises. But they not receive rent with any tends, dec13 have rent receipt but when we gave Jan 14 month rent, they denied to receive rent coz "who sing on rent receipt among 7brother" The same has happened for Feb & march rent. And when try to money Oder to the post office not allowed to issue money Oder in the name of expired person. plz help How can we deposit rent in rent control? We wants to continue to stay in the same premises. I will be grateful if any expert can advise and suggest his legal rights and what steps he should take to safeguard himself under the WB ACT. thanks.