Hi Prashant,

To use a different template for a particular category.

Step 1 create all your single blog category menu item.

Login to your backend->Select Main Menu->Add New Menu Item

In the Menu item type->Select.
http://screen.stackideas.com/Template_style_s1.png

After clicking select a window will appear (please refer to the screenshot), in the menu select->Easyblog
http://screen.stackideas.com/Template_style_s2.png

In Easyblog Select ->Single Category layout
http://screen.stackideas.com/Template_layout_s3.png

After selecting the Menu Item Type you can select the Template style (please refer to the screenshot)
http://screen.stackideas.com/template_style_s4.png

Step 2
Components->EasyBlog->Settings->SEO->Advance Settings

EasyEasyBlog Routing Behavior set to default

Under Category 3 Or, ignore this item: Set to No
http://screen.stackideas.com/template_style_s5.png

Hope that helps

Best regards
Chris