according to the official site 78LMT supports 140 w TDP CPUs
That does _not_ mean that it is fine to overclock a Phenom II X6 on it. lol, your motherboard would get fried if you put Phenom II X6 1055T in that and OC. Without even checking the website, I can tell that your motherboard is a 4+1 phase VRM motherboard. For overclocking, 1055T you need a decent motherboard with
8+2 phase VRMs. Such a motherboard would cost in excess of Rs. 9000 at the very least.
Next, you haven't even changed your PSU.
Listen to me carefully, if you really want to overclock.
Buy these:
AMD FX-8120 @ 12000
Gigabyte GA-990XA-UD3 @ 9500
Seasonic S12II 620w Bronze PSU @ 4800
Cooler Master Hyper 212 Evo CPU cooler @ 2200
You should have thought about overclocking before bought the current PC.