Redeem house after tax sale

Hello Guys,

We have the opportunity to help a person we know redeem its parents house that they lost at tax sale to an investor 8 months ago.

Attorneys seem to say there is a way to file a petition at the courthouse, pay the delinquent taxes and get the title back. In exchange for paying back the taxes, my partner and I would gain 60% equity of the house and resell it (free and clear). We are looking at making at least 50% on our money after resell.

Has anyone been through a redeem process like this one? Does this usually work?

FYI - house is in Pennsylvania

Thanks