i dont know whether this is the right place to ask ....so i just give it a try

Previously i was using UNIFI 5 and in my family there is more than 6 devices connected to the same wifi...so everytime i was playing game...i got some really high ping when they are watching video or downloading.....i thought 5mps is just not enough for 6 devices so i upgraded to 30mbps now....and the problem is still exist...so i need sifu sifu here to help me or teach me to limit speed to other devices...like 30mbps and split to 6 = 5 mbps per devices....so i can still play smooth in game...hope i can get help here   

i have heard of QOS ....but i dont see that option in my D-Link router....so i think maybe my router dont have this feature....cause free from TM ma