Every Indian company carries a 21-character Corporate Identity Number issued by the Registrar of Companies. The Ministry of Corporate Affairs exposes the corresponding master data for free on mca.gov.in: incorporation date, registered office, director list, authorised capital and annual filing status. That registry entry — not a map pin or a directory page — is the legal truth about whether a company exists and whether it is compliant.
Practical red flags when researching small firms include an unclaimed business listing, meaning the company has never confirmed its own details; a care-of registered address, which is legal but uninformative about real operations; and a mismatch between the domain you are visiting and the domain the company's records reference. None of these proves wrongdoing — each simply means 'unverified', and unverified should mean: check the MCA record before paying anyone anything.