(1) In case of pennission under Rule 20 of the sanction once accorded shall remain valid up to five years.
(2) The permission may be revalidated if it not expires. Such revalidation may be permitted for two consecutive terms of one • year each, after which proposals shall have to ·be submitted afresh.
In case the application for revalidation is submitted after the expiry of the said period of five years, the Agency shall charge a permission fee equal to the fee prescribed under clause (a) of sub rule (3) of rule 26 before revalidating the same. However no fee shall be charged if the application for revalidation is received before the expiry of its validity. The limitation of seven years shall not be relaxed.
(3) In case execution of the project begins during the validity of the permission granted under Rule 20, the permission shall not be deemed to lapse thereafter at any time and no revalidation shall be required.