Hello yep,
for the ram you will needto know the model of your motherboard, and the rams you already have in ( providd you don't want to throw all of them out.
as for the graphic card, as long as you don't dual wield, all you need to pay attention to is the socket and your power supply. The model number of your motherboard will tell us the socket type which will be most likely PCI-express, the PSU is a bit trickier ofcourse.
What kind of psu do you have what components do you have in your pc?