i am going with a skylake 6600k build and 750ti with 6 pin power lead and my budget is really tight will it be ok to run the system with a tier 4 psu like a cooler master elite or a corsair vs for example ?
Tier three is about as low as I would go but most tier three PSUs already cost $40-60 and you can get some tier two PSUs like the Seasonic 520-620W S12-II and other brands' models based on the same design for $50-70.