Cheating in home construction contract

I took the home loan of 30Lakhs in Nov - Dec 2018 and gave it to my contractor, E Chenna Reddy. He has started the construction initially but had been delaying for almost an year till pandemic has started while I was paying my EMI. After corona he started again, done a bit and stopped abruptly. Only 70% work is done. He was not reachable and he's not there in his office. My dad who's handling all this house work had been trying to contact him. 2 months before my dad was able to meet him and when asked about the house work, the contractor said, he has no money and so give up and there's nothing he can do to finish the construction. He suggested to finish the work by ourselves and for that he'll pay a total of some 5 to 6 lakhs on monthly basis. But still he is not reachable again. We need to borrow money again from someone to just finish the work. In addition to all EMIs I paid, the rents we are paying, the time it has been delaying and again we are asked to get it finish by ourselves. I'm living in other city and my dad who are there in town is hesitating to proceed legally because they might be influential and threatening. It has been a mental torture for my family and me. I am also not quite aware of the proceeding legally. Please guide me procedurally what exactly I could do to get some justice regarding this. As this construction is also part of the layout, I guess others like me are facing similar issue. Thanks you so much in advance.