Firing the Managing Director by Shareholders of a Private Ltd Co

Our company is owned by two families. Family A holding 75% of shares distributed equally between 3 brothers and Family B holding 25% shares by a single person. Family A has only one Director (A1)in the board and also the person running the company and Family B has two directors including the Managing Director (80 Years old) (B1 and B2). Directors B1 and B2 entered into an MOU to pay a huge amount to an unrelated third party and coerced A1 to sign the same and released first tranche of cash without the consent of A1. No board meeting nor General Body Meeting was held to approve such a transaction. Now A1 has sent a legal notice to the Co, B1, B2 and the third party to whom the money was released against the action and the illegality of the MOU, was against her consent showing proof of coercion, the action of the other Directors against the interests of the Company and other Share holders. B1, is now threatening to fire A1 from the board for the legal notice. This leaves Family A with no control over the Business. Is there a way to remove the MD and other 3 brothers of Family A to find place in board although AOA doesn’t have any provisions for that.