My WIfe has property rights on my Father-in-law and Mother-in-law properties

Sir, my wife she got married with me on July 2003 and we have disputes with her family. but she wants to get her share on her father and mother property & jewels etc.. her father died in 2013 after the Hindu Succession act 2005 (9 Sep 2005). her mother is alive and sometime half minded and has revenge not to give anything to my wife due to her own willing marriage against family. (intercaste marriage) now her mother is getting both pension amount (herself and her husband amount) . so far nothing is given to my wife. my wife wants to claim her rights on both of their parents wealth(property & jewels etc). along with her she had 4 elder sons and they are enjoying the income from the property and agricultural land. moreover every one staying in a joint family . we are not sure whether my wife's father has gifted his property to their sons . mostly all the properties are self earned and only one ancestor property in her village. so kindly please guide what rights she had on her father & mother properties. even now also her mother can gift her property to their sons by their own will (her health condition is half minded and sometime she forgot what she told either in day or week). so please advice. the property is in madurai and she wants to file a case in Chennai to avoid any damage to her life and myself.