@RohithyByreddy The TXT record that you’ve added doesn’t match the Support Guide instructions.
The instructions are here:
https://answers.netlify.com/t/support-guide-another-site-is-using-this-domain-verifying-domain-ownership-for-netlify-production-domain/13765
You’ve added:
The name should be verified-for-netlify
The value should be
https://answers.netlify.com/t/domain-verification-for-missionmerge-com/140607