I've URL plan for my blog such as this: http://www.example.com/%YEAR%/%MONTH%/%CATEGORY%/%POST%5FTITLE%/

Now i wish to redirect a specific category blogs to another domain. The URL Plan on that other domain is comparable.

Please suggest me how do i get it done using .htaccess

Presuming you are using Apache the answer is by using mod_rewrite. The next inside your .htaccess should achieve what you are after. I am presuming that %YEAR% is four numbers and %MONTH% is 2 numbers, adjust accordingly if this isn't the situation.

RewriteEngine On
RewriteCond %{REQUEST_URI} ^(/\d{4}/\d{2}/)([^/]+)(/.*)$
RewriteCond %2 ^category1|category2|category3|category5$
RewriteRule ^(.*)$ http://other.example.com$1 [redirect=permanent,last]

Explanation of every line:

  1. Enable mod_rewrite
  2. See if the url is /four numbers/two numbers/anything/other things
  3. When the above pattern matched up then see if the written text taken through the second group of brackets matches the word separated by pipes
  4. When the above condition matched up then redirect towards the same path in the server other.example.com