i used to run 10 k and well sadly my knees are suffering now mostly my right knee. it clicks at the top of my pedal stroke when knee as its highest point.is there any thing i could do to help?

Check saddle position and height, so your not over extending your leg on the downstroke(should have a slight bend in the knee). I've had similar, joint sounds, coming from my left knee years back. Found out, all I needed was just a few mm of adjustment on the saddle and the creaking stopped. A few mm, does make a difference.

another rule of thumb being that your knee should not be forward of the pedal axle when the crank is at the 3 o'clock position, rather even or just slightly behind.

i had to move my seat back to accomplish this and it made a big difference in comfort for my rebuilt knee.

best option would be to go to a (reputable) shop for an actual fitting. it really does make a difference.

Maybe your knees are bent too much at the top of the pedal stroke? In which case you might need to raise the saddle. I know I had almost immediate knee issues when my MTB saddle dropped too low while out on a ride.

ty for the advice everyone ill try it out

Also make sure you aren't mashing the pedals. Keep a good spinning cadence.