Rent not paid

Dear Sir,

I have 2 rooms in a chawl in mumbai which i have rented for 2 tanent before 20 years (No Agreement made). Now both tenant are not paying rent for 4 & 2 years respectively and also both the tenant are not staying in that room for 4 & 2 years respectively. Both of them are coming once in 3 months for 10 - 15 minutes then lock the room and go back.

So i want my 2 rooms back, Kindly give suggestion & what action to be taken