Is khata transfer a must for sale of inherited property

Sirs/Madams, I am buying a land in Bangalore. The sellers are the wife and 2 daughters of the owner and the owner has expired. The sellers have not transferred the ownership in their name however they have obtained a legal heir certificate from the court and based on this certificate/affidavit, they wish to execute the sale deed. On equiring the genuineness, they clarified that only in case of an agricultural land the ownership needs to be necessarily transferred and then sold. And in case of a non-agricultural land, they can sell the land with the legal heir certificate and all the three legal heirs are willing to execute the sale deed. My questions are: 1. is it ok to sell the land as a legal heir and not obtaining the ownership first and then selling? 2. is it true that non-agricultural land can be sold as explained above? 3. will I face any ownership in future say from he children of the legal heirs (the daughters)? Barring this there is no other issues in the property and I am getting at my desire rate. Hope my questions are clear. Please advice. Regards Vijay Rao