Hi, I am 32 yrs old and I have done masters in engineering digital Communication. Can I apply for Phd in USA?
There is a age limit in USA for Phd admission?

There is not an age limit for admission as far as I know, but some funding bodies may have age limits.

As far as I know there are no age limits in any country. However, be aware that a PhD in the US will take on average a lot longer than in would do in most European countries. You might want to take that into consideration depending on your reasons for wanting to do one. Also, I would advise looking at the job prospects for PhD graduates in your field, if you are seeking to do one for career-enhancing reasons.

I'm 53. I graduated with my first MA at 49. I hope to finish my PhD when I'm 56. Every university I've applied to have commented that they see 'experience' (read "OMG, you're old') as almost an extra qualification.