Property sold with adverse claim and tenants would not vacate

Hello,
I have a question. My Grandparents have a property where 1/5 of this is given to the wife of my mother's Uncle. the property is already sold and partially paid by the buyer. Last November 9, my mom receive an adverse claim from his Aunt with notarized extrajucial settlement with waiver signed in 1981 but it was not registered with the registry of deeds since then. They noticed that 2 of my uncle's signature were forged and the second wife of my grandfather is not included. On the other hand, they are renting the place and since November 2017 my mom gave notice that the property is no longer ours and they should vacate it on the 15th of January but they are asking for a court order. We are actually in one roof separated into 2 doors and if our house will be demolished, their place would also be affected.

The question is, it's been almost 2 months and yet they have not file a case in the RTC. How can we invalidate the claim? If they did not register the deed of donation, do they still have the rights over the property? Agreement with the buyer is that the property will be vacated on the 15th of January but since the tenant will not leave, how can we demand them to vacate the property?

I hope you can answer my queries because my mom is really worried about this since we might be penalized by the buyer because of this.

By the way, tenant ng aunt ng mom ko yung nakatira dun.

pls answer po. naguguluhan kase ako between extrajudicial settlement with waiver and deed of donation. Question pa is bakit after 30 years and nagkabentahan na ngayon pa lang nila kineclaim yung right nila sa lupa.

if they refuse to leave, then you will have to file an ejectment case against them. Under whose name is the property registered to?

The property is registered to my mother's dad but they are claiming that since they file for an adverse claim, they have the right on the land. Yun ginagamit nila para maipit kami. the case is already at barangay level and ayaw na sana namin iparating sa court considering the cost eh napenalty na kami ng 20% of the total contract price because of them. The building is considered to be dilapidated and fire hazard since almost 60 years na yung bahay and sira sira na yung mga kahoy. We cannot sleep because of this kase my mom and his sibling is sure na hindi nila alam yung document na sinign nila. I'll send the copy of extrajudicial settlement with waiver tomorrow.

I mean wala sila natatandaan na pinirmahan.

Try your best to resole this through negotiation. Gather evidence that the signatures are fake. If nego fails, you will have to go to court to remove the adverse claim