23. Mr. Renju,
Show the tax liability alongwith interest in forthcoming GSTR-3B to be filed and avail the tax credit. RCM is Revenue Neutral and does not amount to suppression of facts, .....Don't make any payment for penalty. In RCM, department does not stand to loose revenue if you are eligible for ITC.
It's on the department to establish that provisions of Section 74 of CGST applies in your case and if you have recorded transactions in accounting books, no suppression. Mere notice from department does not amount to fraud, suppression. Department in majority of cases have tendency to issue letter u/s 74(5) of CGST Act and they failed to establsih same in higher courts.
We should understand what exactly Section 74 in context with section 17(5) of CGST Act refers to. Nothing has been concluded or agreed upon by you at this stage as to contravention of Section 74. You pay tax and avail ITC, catera of citations are available of higher courts.