In 30k budget, it will be difficult to fit a Quad Unless you get a Quad in Used for about 10k.
And yes P35 Neo 3 can support Q8400, but i believe you need a BIOS update to the latest one i.e. v1.4
P35 Neo 3 alone costs Rs.8k
So how exactly you are going to fit in it? And if you ask me, increase your budget upto 40k and get a Core i5. Performance wise its much much superior to a LGA775 quad which will cost you almost the same as the cheapest mobo for LGA1156 costs Rs.9500 which is Intel DP55WB, which also supports overclocking.