The Unit Trust of India Act,1963
Section 13. Vacation and resignation of office of trustee
(1) If a trustee-
(a) Becomes subject to any of the disqualifications mentioned in section 12; or
(b) Is absent without leave of the Board from more than three consecutive meetings thereof; or
(c) Being a trustee elected or deemed to be elected under clause (e) of section 10 becomes an officer or other employee of Government or of the Reserve Bank, State Bank, a subsidiary bank or the Trust,
His office shall thereupon become vacant.
(2) A trustee nominated under clause (b) of section 10 who is not an officer of the Reserve Bank or a trustee elected or deemed to be elected under clause (e) of that section may be letter addressed to the Board resign his office and on such resignation being accepted by the Board shall be deemed to have vacated his office.