GST return filing in India is the process of submitting periodic tax returns by registered businesses. It involves reporting sales, purchases, and tax liabilities under GST. Different types of returns like GSTR-1, GSTR-3B, GSTR-2A, and GSTR-9 are filed based on turnover. Returns can be filed monthly, quarterly, or annually. Timely compliance is important to avoid penalties. The process includes logging into the GST portal, entering details, reconciling invoices, and submitting online. Return filing ensures tax compliance, input tax credit claims, and transparency in financial transactions under GST.