What's the option for Administrators if 2 of 3 adminstrator appointed by High Court play foul with ulterior motives?

You have to approach same court for the removal of administrators upon suffcient evidance.

The aggrieved party has to approach court with suit for seeking the legitimate share in the assets to be distributed by the chosen administrator as per provisions of law.

The fraudulent acts of the 2 administrators are to be highlighted before court with documentary evidences in order to establish the claim.