There is no provision under the Companies Act, 1956 relating to resignation by directors. A director can resign by giving a notice of his intention to resign, subject to the provisions contained in the AOA of the Companies. Once he has complied with the procedures of AOA, if any, relating to resignation or he has tendered a letter of resignation clearly specifying his intention to resign, his resignation becomes effective.
THERE IS NO OBLIGATION ON THE PART OF RESIGINING DIRECTOR TO INTIMATE ROC OF HIS RESIGNATION. IT IS THE DUTY OF THE COMPANY TO FILE REQUISITE FORMS WITH THE ROC.
Since your name is included as director in the annual report, you can send a letter to ROC along with evidences to show that the company has been notified of your resignation.