Hey desijays

A lot depends on what your buget is?
As far as bang for the buck, go with the cheapest CPU (Sempron 145), a mobo with atleast 3 PCIe16x slots (Gigabyte UD3 ....risers are hard to find in india), for GPU I find the 280x offer the best hash/rupee value. The 7990 offers the best hash per slot followed by the 290x, PSU - Cooler Master/Corsair - atleast 250watts per gpu (Look for high efficiency one. atleast 85%+). RAM - you can probably get by with 1 GB, but i've got atleast 2gb on each of my rigs.

You will find prices to be cheaper at shops over web. All of these are easy to find if you know where to look.

I've currently got 3 rigs going with 2 R9 280x's on each. Waiting for risers so i can add more. 5 are sapphires & 1 is msi. Prefer the sapphires... getting about 30khs over the MSI.

Have decent CPU's running on 2 rigs for protoshare (cpu mining now dead with gpu miner available), XPM & quarks(diff too high). Been mining dimecoin with the cpu's last couple've weeks.

Rig A
PSU - Cooler Master 1000W M2 http://[Suspicious link removed]/LH9Fc6. Price - 13k
MB - Gigabyte GA-990XA-UD3 http://[Suspicious link removed]/1ekp6Tv. Price - 9k
CPU - AMD FX-8320 http://[Suspicious link removed]/1k3oNic. Price 9.8k

Rig B
PSU - Cooler Master 850W M2 Price - 10k
MB - ASUS H87 Pro http://[Suspicious link removed]/1n7cBdA Price 9.5k
CPU - i5 4670k http://[Suspicious link removed]/1ekpYHG Price 14.5k

Rig C
PSU - PSU - Cooler Master 850W M2 Price - 10k
MB - Gigabyte GA-990XA-UD3 http://[Suspicious link removed]/1ekp6Tv. Price - 9k
CPU - AMD Sempron 145 Price -1.9k (I have an extra one that was used for 2 weeks on Rig B. Willing to sell it for 1k)

Hope this helps