non-obstante clause is a legislative device which is usually employed to give overriding effect to certain provision over some contrary provision

It is well-known that a non-obstante clause is a legislative device which is usually employed to give overriding effect to certain provision over some contrary provision that may be found either in the same enactment or some other enactment, that is to say, to avoid the operation and effect of all contrary provisions.

Union of India v. G.M. Kokil, AIR 1984 SC 1022