The documents required for Indian business visa are as follows :
The foreign national must have a valid travel document and a re-entry permit, if required under the law of the country concerned.
Proof of financial standing and expertise in the field of intended business.
Documents/ papers pertaining to proposed business activity such as the registration of the company under the Companies Act, proof of registration of the firm with the State Industries Department or the Export Promotion Council concerned or any recognised promotional body in the relevant field of industry or trade etc.
It is advisable that you speak to a good immigration consultant once to know about all formalities and documents.