Digital Signature certificate
There are three types of DSCs Class I type is used only for securing email communication
Class II type is used for Company or LLP Incorporation, IT Return E-Filing, obtaining DIN or DPIN and filing other forms with the Ministry of Corporate Affairs and Income Tax Department
Class III type is used mainly for E-Tendering and for participating in E-Auctions
For most business compliance, Class II digital signature suffices.
Issuing Authorities : http://www.mca.gov.in/MinistryV2/certifyingauthorities.html
Generate Digital Signature Certificate http://www.pdfpowertool.com/home/create-test-certificate/