That probably means that your code is flawed, but you just happened to get away with it on the "old" keyboards.

Look at your code very carefully and make fully sure that you are completely & correctly following the PS/2 protocol. Pay particular attention to timing.

Use an oscilloscope to observe the signalling with both old & new keyboards.

"(black color) ps2 keybords are not working;
(white color) working fine"

Clearly the colour itself is irrelevant?

Are all the black keyboards the same make, model & revision?
Are all the white keyboards the same make, model & revision?

I take it the black keyboards do actually work with PCs...?

Do the new keyboards have extra features - such as automatically switching to USB or PS/2?


"Suggest solution"

Get debugging!

Edit:

I note that you refer to "keyboards" (both black and white) in the plural - so how many of each have you tried?