GST registration in India is the process of obtaining a unique GSTIN for businesses. It is mandatory for eligible businesses to register and allows them to collect and remit GST, claim input tax credit, and establish legal recognition. The registration involves an online application, submission of business details, PAN, bank account information, and supporting documents. Once registered, businesses must file regular GST returns and maintain proper records. GST registration promotes compliance, accountability, and facilitates the smooth movement of goods and services within the country.