Issue faced by tenants not paying rent

I have given my room on rent. The tenant paid part of the deposit and requested me that they will give the remaining within 10 days. On request i let them stay in the room. Its been 1.5months still they have not given the deposit. I have just received the rent for 15days. Now on asking for deposit they are saying that the rooms are not in good condition why should they pay the remaining deposit. I have not made any agreement as i am waiting to receive the deposit amount. On asking for the rent for the month of October Even the rent is not being paid. Kindly help as to what should i do as i have asked them to leave they are saying that they are searching for new place from past 10days