okay i have found a simple solution to it. I removed redirection rules from cpanel and add these code to my htaccess file
# Turn on rewrites.
RewriteEngine on
# Only apply to URLs on this domain
RewriteCond %{HTTP_HOST} ^(www.)?rohbits.com$
# Only apply to URLs that aren't already under folder.
RewriteCond %{REQUEST_URI} !^/blog/
# Don't apply to URLs that go to existing files or folders.
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
# Rewrite all those to insert /folder.
RewriteRule ^(.*)$ /blog/$1
# Also redirect the root folder.
RewriteCond %{HTTP_HOST} ^(www.)?rohbits.com$
RewriteRule ^(/)?$ blog/ [L]