Close to UTM, but not UTM

I'm trying to figure out the Projection used by Bhunaksha Rajasthan.

The software uses OpenLayers3. The Khasra maps match very well to the UTM Coordinates, however are just slight off.

Is there a projection in the Rajasthan Region of India, which is very close to the UTM 32643 Projection?

Like using the same numbers but slightly off.

Please DM if you can help me with this, I can share some maps and their accurate images and we can figure out the problem together.