As you want open a company in India and asking for registration, so here is the process for the same:

Registering a startup or a new business in India
These are four major steps:
Acquiring Digital Signature Certificate(DSC)
Acquiring Director Identification Number(DIN)
Filing an eForm or New user registration
Incorporate the company

When it comes to company registration, Every firm will have following two options:
Private company:
Public company:

Step 1: Acquire Director Identification Number(DIN)
Step 2: Acquire Digital Signature Certificate(DSC):
Step 3: Create a account on MCA Portal – New user registration
Step 4: Apply for the company to be registered.

Documents for start a company :
DIN of all those directors of a proposed company.
DSC – Digital Signature Certificate
Original copy the of formal letter issued by ROC regarding availability of Company name.
Form-1 for incorporation of a company.
Form-18 for situation or address of the proposed company.
Form-32 for particulars of proposed directors, managers and secretary.
Formalities to be followed while incorporation of a company:
Obtain a TAN card
Obtain a Permanent account number (PAN) from income tax dept. India
If required: Documents obeying shop and establishment acts.
If required: for foreign trade, Registration documents of import export code from Director General of foreign trade.
If required: Registration documents of Software technologies Parks of India (STPI).
If required: RBI approval for foreign companies investing in India and FIPB approval.
Both Indian and foreign directors need to have valid Digital Signature Certificates from authorized agencies.