Possession Certificate

Property name- SARE homes sector 92 Buying resale property in high-rise society but the seller doesn't have a possession certificate though they have a registry and all other documents like allotment letter, bank NOC, etc. They are ready to give supporting documents required in absence of a possession certificate ie FIR copy, newspaper advertisement, i-bond, NOC from RWA of society. Is this okay to proceed and buy this property or actual possession letter is a must. The bank is agreeing to give loans on the basis of these 4 supporting documents but I want to be sure that in future it won't affect me.