This is the First requirement of a Merger that Specfic Clause must be there in your Object Clause of Memorandum of association that the Company Can Merge/Amalgamate under Provisions of Section 391 to 394 of the Companies Act.
If this Cluase is not there then you are doing thing Which is Ultra vires.
Further,In RD Query Letter,He will specificcaly ask about the relevant Clause of the memorandum Which has given Power to Amalgamate.
Further,Copy of MOA will always have to be attached with petitions.
Further,After Merger No such Other Alteration is required.