This is the last clause of MOA (Memorandum of association) (aka Subscription Clause). A company itself is an association of persons and this association is formed by Memorandum. The individuals who want to be part of this association needs to sign Memorandum of the company, this part where such signatures are affirmed is called association clause. The people signing such association clause are called first subscribers or promoters. The first subscribers or promoters are needed to take at least 1 share of the company.
It shall be signed by at least 7 or more people if it is a public company.
It shall be signed by at least 2 or more people if is a private company.
It shall be signed by 1 person if it is one person company (OPC).
These signatures are to be affirmed and witnessed by public notary as well along with Name and Address proof.
There shall be witness for every single signature. There can be 1 witness for all the signatures, but none of the subscribers can be witnesses of each other.
Note: In case Association contains an artificial person, MOA of company to be formed shall be signed by designated partner in case of an LLP, or by Authorized Board member in case of Company.