Dear Abhishek,
Appointment and resignation of directors are governed by the provisions of he Companis Act, 1956 and the Aritcles of Association of the Company. A Director is free to resign at any point of time. Unless the Articles provide for acceptance of the resignation, it becomes effective from the time when such rsignation is tendered. [T.Murari v. State, (1976) 46 comp cas 613 (Mad) & S.S.Lakshmana Pillai v. ROC, (1977) 47 comp cas 652 (Mad)]. Directorship and membership stand on different footing. In a public limited company shares are freely transferable. It is for the company reuse registration of transfer in which case he can approach the CLB for directions to the company for approving share transfer.
Regards.