The article fails to differentiate between charges and conviction. In India anyone can get charged for a crime no one ever gets conviction.
As an Indian I think Criminality of Indian Politicians is a non issue. Very few of the politicians are actual hard criminals. Most face charges that anyone in important position is likely to face.
Nearly all my politician friends have been in jail and have criminal records but I can vouch they are pretty good people.
India does not uniform laws and far too many laws to deal with the exactly same crime.
Examples:
1. One of my friend has been fighting in court for last 7 years over a case registered on him by his political opponent. My friend called him "asshole". However as per Indian law it is a crime to abuse a person if the person belongs to specific caste (SC/ST) not just that, the police are required to register the case even if they think the charges are frivolous or unsubstantiated. This gentleman has been visiting court every few months. The charges will be dropped some day as a political bargaining chip.
2. I barely escaped having a criminal record when I participated in a political movement. The cops basically filed any random charges against the protestors including molestation, attempt to murder and what not. I escaped because I had a fake ID card with fake name on it.
3. A lot of civil offenses are "crimes" in India.
For example you are CEO of a publishing company that publishes a scholarly book on world mythologies. Some person files a complain saying you (CEO) has hurt the sentiments of public which is a criminal offense. India Ebay CEO was arrested as a criminal becomes someone sold a CD on the website that had porn clip in it !
4. Courts that don't work.
Indian courts spend time only on cases that make the judges popular. Such as cases that involve celebrities or cricket. That is why conviction rates are next to nothing. One Indian celebrity recently got acquited from tow major crimes after around 12 years of fight.
5. Drinking wine or beer might be a crime in some states and in one state they want to give capital punishment for the same.
6. Eating beef might be a criminal offense.