Originally Posted by fahadk

No its not. As an example consider this:
Suppose there are 5 seats for each category. 500 apply for management sciences category, 100 apply for engineering, 200 for computer science and 5 for xyz category. This way all of xyz category are selected without being tested even if they are poor performers, on the other hand many qualified applicants from other fields will not be able to secure their position on merit. That is the reason categories are disregarded and the best are chosen, irrespective of their fields.