Ram is the necessary computer parts to run the computer and to run programs and games. So you need to buy ram carefully.There are 5 type of ram. This are DDR1, DDR2, DDR3, DDR4, DDR5. The DDR3 and blow the Ram are old ram. This Ram has low latency, low frequency and low capacity. but the DDR4 and DDR5 are the new Ram with high capacity and high frequency.
1. Check the Ram frequency and check the frequency of the motherboard and processor. most of the ram can be overclocked but if motherboard doesn't have the limit then you can't overclock the ram. and also check if your CPU does support 3200 mhz or not. most of the AMD 5000 and 4000 series support 3200 mhz but the old doesn't support 3200 mhz. A large number of intel CPU doesn't 3200 mhz. if you have 3200 mhz ram then it can run it but you will not get the speed.
2. if you want to turn on XMP profile then you need to use the same latency of the dual channel ram. The latency look like this "17-17-17-39" and there is another thing called CL and it should be same also. The most safe thing is to buy the same company Ram if the capacity and frequency is same then you don't need to worry but if the company isn't same then check this thing.
3.If your game is getting low FPS then check how much Ram is your total system is using. if it use 100% then you need to upgrade your Ram but if your system doesn't use 100% rather then use 70-60% Ram then you don't need to upgrade ram you need upgrade other PC parts like CPU GPU or SSD.