According to requirement of business one can choose which type of entity you want to form. there are multiple options.
1. Proprietorship
2. Partnership or LLP
3. Company
4. Foreigned Owned Company. etc

Secondly, Entity required to obtain all the registration and licenses which is applicable for activity of business.

License and Registration List for Startup Business

PAN Card: Income Tax Permanent Account Number is Compulsory for starting Business In India. However Individual Proprietor Not Need to Apply Separate Business PAN. for all other types of Business Establishment PAN separately available from Income Tax Department.

Professional Tax Registration/ Shop Act License: Before Starting Business activity, Establishment Need to Get Registration Certificate from Local Municipal Corporation. Such Registration are as per Local Municipal Area Guidelines. Types of Registration are Professional Tax Registration, Shop and Establishment License, Gumasta Dhara License etc.

Goods and Services Tax Registration (GST): Supplier of Goods or Services are Required to Get Registration under GST Act. Minimum Turnover without GST is upto Rs. 40 Lacs. However for Interstate Sales and For Export Sales GSTIN (GST Number) is Compulsory. Goods and Services Tax is Combine Tax Structure of Service Tax and Sales VAT Tax.

Tax Account Number (TAN): Person or Establishment Responsible for Tax Deduction at source are required to get TAN. Its Mandatory for the entity who is required to get tax audit of their Books of Account.

Provident Fund Registration (PF): If employees are morehan 20.

ESIC Registration: If Employee Morethan 10.

Special Registration According to Business Activity:
Labour License: in case Manpower industries.
DoT (TRAI) License: in case call center and BPO, KPO activity
Foods License (FSSAI): Hotel, Restaurant Units
Drug License: Medical Store
Import Export Code (IEC) : Exporter

After All License and Registration, Business bank account need to be open with bank for payment and receipt of proceeds of activity.

All the accounting records of business sales, purchase, expense should be maintained time to time. All the Application return must be filed within due time.