IEPF Recovery company?

I’m working on estate matters where stock market shares are with the IEPF and need to be “recovered”. The typical stock broker / wealth manager does not do such work and there are various companies which “specialize” in such operations. I am an NRI and live abroad and have a brother and a sister who live in India and we three have an equal interest in this. The three of us are working together on this but they’ve asked me to lead the effort. I’d like to do some due diligence before we select one of these “IEPF recovery” companies and sign a contract. Are there organizations in India which track complaints / records of such “IEPF recovery” companies or in general track consumer complaints of financial organizations? Any ideas as to how I can do “due diligence”? Anyone in this group have any experiences? I’m hoping the Quicko moderators can offer some suggestions.

Thank you!