Different cultures have different laws. As much as we may see certain behaviors unacceptable, another culture may see it a different way. While we may not agree with this, we still should accept the fact that people see things differently. That said, if he violated the law in Bangalore, then yes, he most deinitely should be prosecuted.
No, the Indian minister who said groping at a New Year celebration in Bangalore was due to women dressing like Westerners should not be prosecuted. While what the minister said was extremely insensitive and irresponsible, it is within his rights to state his opinions without fear or being prosecuted for doing so.
Regardless of the accuracy of his statement, he is entitled to express his opinion and he has not violated any laws, so it is absurd to consider filing charges against him if he did not commit any of the alleged offenses. Regardless of whether one agrees with or disagrees with his opinion, curtailing his right to express his opinion is a far greater threat to society than alleged gropings at a New Year's Eve celebration.
You cannot prosecute a person just because you don't like what he said. Was it true or fair for him to make such accusations? Absolutely not! But should he be held responsible for the actions of others? Nope. He is ignorant, that's for sure, but he wasn't the one groping and fondling women (that I know of) for the way they dressed. He just made a stupid comment about it.