Uncle asking for claim in flat after 25 years of transfer to nominee

Hello all please solve my issue its has stressed out my mom for the past few days and driving her crazy My great grand mother transferred her flat to my grandpa as an nominee before passing as he never got educated and made sure his 2 young brothers get education.. then these ypunger brothers B and C bought their own houses and never objected for a claim. Now C's son who dosent have a job and has already sold C's house is eyeing at our house that has my parents as nominee. He has a house outside the city where he lives and so does his dad. My great grandms dies 24 years ago and grandps 10 years ago. Csn C ask for legal heir share. This is what i read Online ::::::: please help me as my dad isn't quite educated so he can be fooled easily. As per the provisions of the Limitation Act, 1963, the time limit prescribed to institute a suit for possession for enforcing a right relating to an immovable property is 12 years. Thus the legal heirs of the original owner are barred by law as per the provisions of the Limitation Act and cannot file a suit today, i.e. 25 years after the property was transferred by the original owner to the subsequent owner. Thus the claim of the persons claiming to be legal heirs of B is barred. In the event that the legal heirs of the original owner (B) are trying to deprive you of your possession of the said property, you may file a suit before a court of competent jurisdiction for declaration of title under section 34 of the Specific Relief Act, 1963. However a suit under the said section can only be filed against a person who is denying, or who is interested in denying, a person’s title to any legal character or right in any property. In the present situation, unless the legal heirs of the original owner are attempting to interfere with your possession of the immovable property, it would not be advisable to file a suit under the said section 34 of the Specific Relief Act.