it's possible to connect two domain using SAML Single Sign-On for only one SF account ?

Hi @Jyoti Muthreja,

Hope this helps! :) This is an interesting question, but I am not sure.

However, it is possible to configure multiple identity providers on the same org: 

• Use cases example: Users located on different continents has a specific IdP. Therefore, configuring 2 IdPs will allow users to choose their respective IdP based on their preference to sign in to the login page.

You may refer to the reference below:

https://help.salesforce.com/s/articleView?id=sf.sso_between_multiple_orgs.htm&type=5