Creating an atlas sandbox cluster

when i just logged in and then as in that video mentioned that creating cluster is free and you have to select MO instance size but i was selecting that option it displays this…

Hi @Akash_06246,

Please check that you might have used M0 tier cluster in the project. So, you are not able to see the free tier option here.
However, you can create a new project and then create M0 free tier cluster. You can refer to the following post for the same:

Please let me know, if you have any questions.