House owner

I have been staying in this particular house for more than 3 years now. this house was not done completely when i shifted but i thought the owner would get everything done asap but that was not the case.......for the first 7 months this man was not even bothered, when i didn;t pay 7th month rent, he got certain things ready. there was one mesthri who used to accompany him during those 7 months and used to give me dirty looks also but never used to get the work done. this sink and wash basin would always used to leak every now and then, it was no use telling him about it like as usual. now this owner is taking advantage of corona situation and told me the kitchen pipe is smalll, that;s why the leakage. and he;s blaming the mesthri for it......plus there's ceiling also started leaking during rain. i don;t understand who gives right to such people to give house on rent? are there no basic rules for it? owner always behaves like as if he has come out of coma and starts explaining what is causing the problem.....i am not interested in his explanations, i want this man to get the work done..... what should i do about it? plus this man had threatned that he would throw me from the third floor when i pointed out his mistake. he's not paying income tax for the rent as i have beeen asked to pay him in cash.i have call recording where he has thereatned me. and also the call recording of the plumber who did the plumbing work for this building stating owner knew that the kitchen pipe was small from the begining.