This Problem is related to Backend side (Magento 1.9 Admin panel) not for Frontend side:
Part: 1) - I wanna Create Custom tab (suppose 'CategoriesInfo') in magento 1.9 admin panel. (like parallel to other top side tabs like, Dashboard,Sales,Category,CMS and etc ) - This tab has one sub_tab, 'categoryIDs' - When you click on 'categoryIDs' sub_tab, it'll show one page at admin panel where i can write my logic to fetch all available categories.
Part: 2) - It will show all the Catagories and sub_categories IDs and Categories name with Checkboxs. - Admin can select any category then click on save button then data should be save into file/DB (for now in file).
Please Share Your ideas, Your ideas and efforts are appreciable for me, Thanks.