mrigank_2 :
my res is 1366*768 and i am living in India
Well, even at 1366x768 you can benefit by using a high anti-aliasing such as 8xMSAA so the extra processing of the GTX1050Ti is important. I don't think you'd likely use more than 2GB of VRAM but I could be wrong... though swapping back to desktop would be faster if the game doesn't have to swap the DESKTOP VIDEO data to system memory or even the HDD paging file (if confused, just read as "games may start and close faster with 4GB of video memory").
If it's straight up a budget issue the GTX1050 is a bit cheaper but not enough that I would choose it.
Anyway, I think all the points have been brought up:
1) 3GB of system memory is a problem for gaming (8GB in 2x4GB kit recommended)
2) GTX1050Ti low-profile seems ideal
3) Power Supply appears inadequate, hence the 300W or 350W models I linked.
I'm not sure what else to say as you really need all three things to have a proper gaming experience. 3GB only of system memory will cause major stutters and freezes in many games, not replacing the PSU may cause instabilities, crashes or even cause the PSU to fail and potentially wreck other components.
And not upgrading the GPU makes the PSU upgrade pointless (though more system memory can help web browsing etc a bit).
Other: you'd have to investigate FLIPKART or other India sources to find these parts and the best prices. I find it a big hassle to search those sites so I use PCPARTPICKER and hope you can find something comparable