How To Get An RTC In My Name Which Has No Records But Is Under My Position

I had purchased land measuring 1 acre in a village of Mysuru, Karnataka in 2008. From that 1 acre land, I sold 0.26 acre in 2011 and the remaining 0.14 acre has no records but was under the position of the person who sold the land to me for 100 years and now is under my position and I'm cultivating in that land. According to the sketch of that survey number, the 0.14-acre land which I discussed earlier is not shown and is someone else's(according to the sketch) and that someone else also thinks that 0.14 acre is my land only and the land is actually available(if we measure the full area) and is under my position, there is no dispute from others as this was the situation since 100 years. Now according to land law, what are the provisions through which I can get an RTC in my name and get the sketch modified legally. How can I get the records of this land. Please Help. Thank You.