Time limit for notice : (a) No notice under section 148 shall be issued, (a) in cases failing under clause (a) of section 147 (i) for the relevant assessment year, if eight years have elapsed from the end of that year, unless the ease falls under sub clause (ii); (ii) for the relevant assessment year, where eight years, but not more than sixteen years, have elapsed from the end of that year, unless the income chargeable 720 to tax which has escaped assessment amounts to or is likely to amount to rupees fifty thousand or more for that year; Section 150(1) makes an exception in cases where assessment or reassessment is sought to be made in consequence of or to give effect to any finding or direction contained in an order passed by any authority in any proceeding under the Act by way of appeal, reference or revision and provided that in such cases there should be no time limit and notice under section 148 may be issued at any time unless of course the case fell within sub section (2) of section 150.