Redeeming what's been renounced unlawfully

There is definitely an issue here, but you are right, you do not know how to explain it.  Contact a lawyer on the phone to help.  Documents need to be reviewed.

I think I understand your question. Your grandmother passed away, and you're concerned that her property and land are not going to the people she intended. The only way to determine if that's true is to see her will and the deed to the property. If your uncle "took over" that likely means he's either been appointed executor or is trying to be appointed, and it's also likely that he retained a lawyer to help him. If your uncle and/or his lawyer are unwilling to give you information, you need an attorney to communicate on your behalf.