No patta/chitta for the land however paying property tax

Hello Experts, My father bought a porampoke land on my mother's name in early 1980s and we have a property document of the sale. During late 80s, the government was issuing patta for our land and adjoining lands however due to personal circumstances we were not able to complete it. Now, all the lands around our property are properly registered and are with patta/chitta whereas ours is the only land that doesn't have the patta. However, we had been paying the property tax all along. My mother, who is now widowed had been running from pillar to post to get a patta for it and in the process lost some money. My father passed away in 1995 and he was an ex-serviceman. Myself and my siblings are settled away from our home currently and my mother is very attached to this land given it's from her late husband + all the mental agony in her frail age. I would appreciate your advice as to whether we can get the legal documents/patta at all in this circumstances. Thanks in advance.