Hi Vinay! Julianne from Mixpanel Support here.
If you're looking for an existing project and can't find it, it's possible that you haven't been invited to that project. In this case, you would need to ask an Owner or Admin of that project to invite you.
If you have already been invited to the project but don't have access, can you submit a ticket here? When you submit the ticket, it would be helpful if you included information about the project you're trying to access.Â