hey, as you're from india, i can suggest a good site
https://www.theitdepot.com
First I shall talk only of the rig.(excluding peripheral devices)
At the site, they sell combos,so get
1.Intel Core i5 6th Gen 6500 3.2 GHz + MSI B150M PRO-VDH 64GB DDR4 + G.skill 8GB (1 x 8GB) 2400MHz
2.Asus GTX950 2GB DDR5 Graphic Card (GTX950-OC-2GD5)
3.Deepcool Tesseract BF Mid Tower Computer Case - Black
4.Seagate Barracuda 1TB 7200RPM SATA Internal Desktop Hard Drive (ST1000DM003)
5.Deepcool 500W Power Supply 80Plus Bronze Certified (DA500)
This rig would level off at 50k, you would have to purchase other peripheral devices like keyboard, mouse, speakers and monitor
But if u want everything within 50k ..well here's what you've gotta get>>
1.AMD FX-Series FX 6300 6-Core Processor
2.MSI 970A-G43 32GB DDR3 AMD Motherboard
3.Kingston HyperX Fury 8GB 1866MHz DDR3 RAM - Red
4.Asus Radeon R7 360 2GB DDR5 ATI PCI E Graphics Card (R7360-OC-2GD5)
5.Toshiba 1TB 7200RPM SATA Internal Desktop Hard Drive (DT01ACA100)
6.Deepcool Tesseract BF Mid Tower Computer Case - Black
7.Corsair VS Series VS450 450W High Performance Power Supply (CP-9020049-WW)
with this you would have around 13k or 14k remaining with which you could purchase a decent monitor,keyboard and mouse!
On a side note the msi 970A-G43 has crossfire support so that in future it may come to use!
Wish u Luck!