Family property mess in Varthur, Bangalore (1950s land sold by co-heirs without consent) — looking for advice

Hey everyone, posting on behalf of my mother and her sisters. We are stuck in a heavy property dispute in Bangalore and need advice on how to navigate this.

Background:

The Land : 2 acres in Varthur bought by my grandfather in the 1950s. He passed away in 2000, leaving 5 sons and 4 daughters.

The Problem : In 2006, all 5 sons and just one daughter signed a sale agreement with Ittina Groups(Koramangala HQ). My mother and her other two sisters were completely left out and never gave consent. We are denied entry to the property now.

Current Deadlock: We tried the legal/court route and settlements before, but lawyers and mediators just took money and did nothing. My aunts now refuse to spend out-of-pocket cash. We are open to a percentage-based agreement if an investor or legal professional can step in, fight it out, and force a resolution with Ittina Groups.

Has anyone dealt with something like this? Is there a realistic way to handle this without burning more cash upfront?

I am open to answer any of your question.