I just started reading about Indian laws out of interest. After going through The Constitution of India,
I am not able to understand what was the ground Supreme Court took for rejecting NJAC as unconstitutional? Selecting judges is not under the Preample of the constitution, so don't the parliement have the right to amend the constitution regarding this?
Preamble doesn't have the status of the bible. in fact Preamble itself was amended vide the 42nd amendment. parliament's right to amend the constitution is limited by the basic structure principle (kesavananda bharati vs state of kerala).
there are several arguments in favour of the collegium system the foremost being the independence of the judiciary.
Constitution is truly an interesting subject. you may go through the constituent assembly debates available on Rajya Sabha website.