[KuhakuWolf]

I like to play mmorph and rpg games like dark souls ect. I also enjoy playing league of legends sometimes.

I was thinking nvidea g1060 3 gb might be suffient but I'm not entirely sure.

The GTX 1060 (3GB) will easily handle the above games.

I recommend opting for the "6GB" GTX 1060. It may be somewhat of an overkill for your usage now, but It's always good practice to accommodate for future needs and developments.

If you want a build that would last a couple years go for the 6g version
Im rocking one and it handles pretty much everything in max settings in 1080p

Since you have a 1k to spend i recommend the build i have
MSI B350M Mortar.
AMD Ryzen 5 1400.
Corsair Vengeance LPX (2 x 4 GB, DDR4, 3200 MHz, C16), minimum 8g more is welcome.
Corsair VS550, but any 500w power suply is enough.
WD Blue 1T, if you want ssd defenatly go for a nvme based like Samsung 960 EVO.
Gigabyte GeForce GTX 1060 G1 Gaming 6G.