Actually, if you get house for rent in like a gated community or in like a proper residential locality like Avinashi road and Ramanathapuram, then 10 months rent money in advance, but if you go for multi-story buildings or independent houses, the landlords sometime reduce and negotiate the deposit money, they might exclude a month or two’s advance.
I think the normal trend throughout Coimbatore, and not just Ramanathapuram or any other major area for that matter, is 10 months advance. No landlord will ask anything more than that for sure.