What happens to stock someone owns/owned in a revoked(and deleted) company.
Nothing happens to the stock. You'll still own it, but it'll be stock in a private company. Your broker will continue to hold it in your account, but it'll be identified by a number, not the ticker, because when registration is revoked, the stock loses the ticker because it's no longer qualified to trade.
Can a revoked company re-apply again after some years?
It can reregister stock as soon as it's prepared to file a Form 10 with the SEC. If it does that, the Form 10--which is complicated, and requires audited financial statements--will become effective in 60 days. Next, the company will need to find a sponsoring market maker to file a Form 211 with FINRA. Forms 211 are also complicated, and FINRA can request more information than what's initially submitted. FINRA approval is likely to take several months. Those are, however, optimistic numbers. It can take longer.
And if yes, does this happen a lot?
I wouldn't say it happens "a lot". Many companies whose registration has been revoked say they'll file a new Form 10, but most of them never do. You won't know whether yours will until it does.
