Concept of Legal heir certificates and succession of property to the family members.

Dear Sirs / Madams, Recently, i lost my father and have come to realise that loosing a father is already difficult and then when one goes through the agony of proving to everyone that you're a son, daughter and wife, it hits you badly even more. I wanted to know. What is the concept of a legal heir certification, when all certificates since we were children prove that we are children of our parents. Be it birth certificate, SSLC, HSC, Passport, ration card, Aadhar, etc. Then why does one go through the hassle of requiring another document; legal heir to prove we are family members? I've been running from pillar to post for the last 3 months to acquire this document and no one seems to give the right answers. Local courts are not facilitative and neither are municipality offices, that we ought to choose agents to do our job, although the time specified is 45 days, I've informed it could take 1 year if we wait for it. So my questions to you all is, how can i find my way through this process? Secondly, my father owned agricultural land, we would like to transfer it to my mothers name. We've been informed by the MRO office representatives that, Legal heir or family membership certificate is necessary along with some of the other documents. Is there a simpler way to do this? given that she is afterall the wife and we have all the proofs required for that. FYI.. my father didnt write a will, so we dont have one document. Any legal suggestions and approaches will be hugely appreciated. Best. Prem.