Tax on cash Distribution

Participant under 591/2 wants her $6500 cash from a profit sharing plan.

How much must be withheld by the plan administrator (is it still 20%)

Is the withheld amount sent to the IRS  with form 945?

The IRS has all your answers here:

https://www.irs.gov/individuals/international-taxpayers/pensions-and-annuity-withholding

If it's eligible for rollover then mandatory 20% withholding applies. I'm assuming the participant has an in-service distributable event under the terms of the plan.

If it's a hardship withdrawal, that's not eligible for rollover. I believe the presumption on those is 10% federal withholding but a participant can elect a different amount even 0% on form W4-R.

As for timing and submission of withholding see ESOP's link.

edited for Bill's correction.

41 minutes ago, Lou S. said:

If it's a hardship withdrawal, that's not eligible for rollover. I believe the presumption on those is 10% federal withholding but a participant can elect a different amount even 0% on form W4-P.

W4-P is for periodic payments. W4-R is for nonperiodic payments.

And it's very difficult to not spell "periodic" as "idiotic" most of the time.