Section 90(4)(a) in The Goa, Daman and Diu Secondary and Higher Secondary Education Rules, 1975
(a)A permanent employee shall not leave or discontinue his service under the Board, without giving a prior notice in writing to the Chairman of the Board of his intention to leave or discontinue the service. The period of notice shall be three months (90 days) in the case of employee in categories 'A' and 'B' and one month (30 days) in the case of employee in Category 'C'.