Q:
want to buy a gpu (from 60 to 100 euros with vga(d-sub) port to play overwatch in low.
A: Looking at the motherboard manual :
https://www.msi.com/Motherboard/support/K9N6SGMV__K9N6PGMFI__K9N6PGMF.html#down-manual
I can see in the specifications of it , that your pcie slot only supports x8 speeds not x16, highlighted below, please note the restriction of video cards as well noted in the manual
Now all that being said, there is a note on page 9 regarding your bios needed a change for the new video card to be functional once you get one
System default is to disable the onboard VGA when you insert a PCI-E graph card, in order to
optimize the system performance. If you would like to use both onboard and expansion card
graph functions, you have to enter the mainboard BIOS and select Advanced Chipset Features
-> OnChip and PCIe VGA selection -> Both exist and Oncip VGA by frame buffer select.
Now with a budget of 60-100 euros, including shipping costs, and the minimum requirements of overwatch for example;
Ref:
https://www.systemrequirementslab.com/cyri/requirements/overwatch/12955
Here are the Overwatch system requirements (minimum)
CPU: Intel Core i3 or AMD Phenom X3 8650
VIDEO CARD: Nvidia GeForce GTX 460, ATI Radeon HD 4850, or Intel HD Graphics 4400
and
Overwatch Recommended Requirements
CPU: Intel Core i5 or AMD Phenom II X3, 2.8 GHz
VIDEO CARD: Nvidia GeForce GTX 660 or ATI Radeon HD 7950
I would say considering your budget your looking at the following choices, GeForce GT 730 4GB, GT 1030 2Gb, Radeon R7 240 2Gb,
all these would be new and none of these would be half the power of a GTX 660 or HD 7950, and less powerful than the minimum requirements of a GTX 460, so my suggestion is find a Used GTX 660 or AMD HD 7950 on eBay or used market for half to same price of a new GT 1030 and truly enjoy the power of it.