56: Orders against which No Appeal or Revision shall lie:

No appeal and no application for revision shall lie against-

(a) an order or notice under section 24, section 25, section 26 and section 29 initiating an enquiry for assessment or reassessment;

(b) any order or action under section 42 or sub-section (1), sub-section (2), sub-section(4), sub-section (7) and sub-section (8) of section 43 or sub-section (6) of section 48.