Mistry, in his representation to shareholders contesting his removal as the director of Tata Consultancy Services, said future of the Tata Group lies in how the trustees govern the Tata Trusts.
"Trustees are required to discharge their fiduciary duties by applying their minds to matters before them, questioning, testing, debating, checking and balancing. The conferment of all decision making power in one man or a high command among them is unethical, improper and a breach of trust," he said.
He further said: "It is critical that serious decisions of severe magnitude and consequence are not taken whimsically, without much thought, or for unstated collateral objectives.
It is necessary to have a strong method of checks and balances in the trustees' decisions, particularly if decisions they take could indirectly give them personal benefits."
He also alleged that Ratan Tata and former vice-chairman of Tata Sons N A Soonawala dictated the trustee-nominated directors as to how Tata Sons should conduct itself.
"They interpreted the Articles of Association to mean that they could call for information and seek discussions on any subject they considered material. In the view of these trustees, the board of Tata Sons was answerable to them and through the trustee-nominated directors, they could not only call for such information but also dictate what decisions must be taken by Tata Sons," he said.
Mistry added that he "did not join the Tata Group to craft a personal image for myself", but was determined to make the "Tata Group stronger and resilient to endure future challenges".
On November 10, Tata Sons removed Mistry as chairman of India's largest software services firm, Tata Consultancy Services (TCS). Tata Sons holds a 73.26 per cent stake in TCS.