ST Land related rules in India

ST Land related rules in India
ST Land rules in India,West Bengal

My father bought a land from an Tribal woman almost 40 years back and we're staying there for this long time. We've the papers where each and every details have been mentioned. We did one mistake by not recording the property in BLRO office.
 
 My father has paid the property tax for this long years. Recently we went to an advocate to record the property legally, but some of them are saying it's not possible to record as it's a ST woman's land. The current paper we're having there it's mentioned that under section 14C the woman is giving permmisaion to the land and she has no right to create any scenes later on. Now her ancestors are demanding huge money then only they will sign in no obligation paper.
 
 So, what's our Indian Law states about this? Is there any thin ray of hope we can record the property without giving money to them?Â