how to show sidebar on homepage

It depends on the theme, but try this:

1. Go to wp-admin > pages > add new

2. Set that page with sidebar template (if exists)

3. Then go to wp-admin > settings > reading

4. Set “A static page” to Front page: The page you’ve created.

If this doesn’t work, then you might have to edit the home.php template file. It’s recommended to create a child theme for customization

http://codex.wordpress.org/Child_Themes

If you are using a commercial theme, usually it has it’s own options to change the Homepage layout with or without sidebars, ask the theme author about this.

That’s a commercial theme

http://themeforest.net/item/flexform-retina-responsive-multipurpose-theme/4258755

you’ll have to get support from them directly.