How to bring about a cause of action when tenants’ rights have been violated?

First of all, I thank you for taking time to go through this question, sir/madam. I am a tenant of a house belonging to the domicile of Karnataka. About two months ago, the landlord asked us to vacate the house since they would be constructing a house above our house. Due to some personal reasons, we asked them to give us time till May, 2019 to vacate the house. Despite that they began the construction work and in order to build a water reservoir, they cut down water supply to the house. Since a month and half, the landlord has cut off water supply to the house and it has caused a lot of problems in the house. An elderly lady, my grandmother suffered slip disk since she had to carry water and fill up all the vessels. Although, they are supplying water with a pipeline, recently, they have been providing insufficient water supply or reduce the pressure of the water flow causing us problems. Kindly, tell us the course of action to be taken under the law that would help us deal with this issue. How do we bring an action against them? Yeah