Owner's daughter filing case regarding transfer of property, advise

My dad purcahsed a land from the vendor 27years back at hosur.the vendor divided the land into 12 layout sites. 12 people purchased from the vendor and we r also one of them. The property belongs to vendor's deceased father. Now We built a home for us and many rental houses upon the land many years ago. The vendor has 4 sons and 4 daughters. His first daughter got married so the vendor didn't mention his first daughter name in sales deed as in 1990 there was no rule that grandparents property goes to granddaughter. Remaining 4 sons and 3 daughters name mentioned and they were minors so didn't sign . we don't know the his first daughter was major or minor during the registration.now the vendor has passed away. His first daughter got jealous on us & trying to file a case only on us and not on the other 11 peoples who were all purchased.can they win??