How long is a travel insurance valid?

An international travel insurance can be availed for a period of 180 days at a time. You can extend your travel insurance if needed.

https://www.hdfcergo.com/blogs/travel-insurance/how-and-when-you-should-renew-your-travel-insurance-policy#:~:text=An%20international%20travel%20insurance%20can,your%20travel%20insurance%20if%20needed.