Sentora Cpanel working perfectly

[TGates]

I have no idea how Mautic works or deploys so this may not help all that much except for getting your domains working properly.

-> I want MAUTIC application to be setup with SENTORA PANEL as a default application which will get installed once someone registers on the website.

From the sound of it you want a new user to go to your registration page and when completed, Mautic, their Sentora account and a subdomain should be created? If so, you would need to create a module and use the Sentora XMWS api to do the work automatically. It is not something that can be setup 'over night'. It would require a LOT of custom programing.

-> I have created DNS on AMAZON ROUTE 53 and made changes.

-----> I want www.domainname.com to go to a seperate page where the ONE-CLICK mautic installation will be showed.

You need to install mautic or whatever your one-click setup is into your domainname.com's root folder (/var/sentora/hostdata/username/public_html/domainname_com/)

-----> Right now, both www.domainname.com and all the sub-domain name are redirected to -> SENTORA PANEL, how do it change that.

You need to add the domains/sub domains inside Sentora also (Domains or Sub Domains Manager). Your DNS does not know where to go except to the server IP (which is the panel login).
FYI: You do not need to use the DNS Manager if you are using external DNS control. only the Domains/Sub DOmains managers.