Article 14 of the Constitution provides to all (irrespective of citizenship), equality before the law and equal protection of the law. I would rant about Salman Khan here, but the fact is that he did face prosecution. Compare this to Madhya Pradesh governor, Ram Naresh Yadav, named as an accused in the Vyapam scam, who could not be touched because of the immunity he enjoys by virtue of his position.
Note that this is not a violation of the Constitution-the law of the land allows for these exceptions. It is interesting however that this immunity from criminal proceedings is available only during the term of the governorship. It should be quite an easy thing to remove the governor (only an executive order is needed for this unlike in the case of the Presidency where an entire procedure for impeachment has to be followed), and then prosecute him. Then again this seems to be too much to expect given that nobody seems to have been touched by the Vyapam scam, except for those who have been deprived of seats and those who have been, well…dying.
Another example of these exceptions at work was when a Saudi diplomat walked off after being accused of raping 2 domestic workers at his home. To ensure that the two Nepalese women now get equal protection of the law, we have to depend on the Saudi government to waive the immunity. Keep your hopes in check, on that.