On Registration of a Company under the Companies Act 1956, the concerned Registrar of Companies (ROC) under which the Company was incorporated issues a ‘Certificate of Incorporation’ to the newly Incorporated Company.
As per the Section 35 of the Companies Act 1956, this Certificate of Incorporation of a Company, once issued to the newly Incorporated Company shall be a Conclusive Evidence which implies that all statutory requirements in respect of registration and of matters precedent and incidental thereto have been complied with.
Ans: In its simplest interpretation, it would mean that this issuance of the certificate of incorporation by the Registrar of Companies overrides any irregularities which may have occurred during the formation of the company.
The Existence of the Company will remain invariable and unassailable, even if there were some fraud/omission of information/unfulfilled formalities etc at the time of formation/registration of the Company and the ending of the existence of the Company will only be possible with the winding up of the Company and not by cancellation of the Certificate of Incorporation.
Some of the relevant Case Laws:
Salim Akbarali Nanji vs Union Of India (2002)
Moosa Goolam Ariff v. Ebrahim Goolam Ariff 
Mohsinali Mahomedali And Ors. vs The State Of Bombay 
Cotman v Brougham  AC 514 - UK company law case.