I need to attach more then 10 pages in the site , Is there any alternative way to add more then 10 pages in site
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No, but with Appian 23.3 you can use page groups and drop-down menus.
docs.appian.com/.../Appian_Release_Notes.html
...and to elaborate a bit more here - in 23.3 a Site can have up to 10 page groups (each of which acts as a drop-down menu) and each page group can have up to 10 pages - so that's a total of 100 pages per Site.
If you want to implement before 23.2 upgrade, As an alternate, you can have page like Home and under that you can create multiple tabs (in an interface) and display respective data dynamically when they click on the tab.