Its probably because I'm about to join an organizatin known for its debt ratings that this idea took shape in my mind, but it sure desserves further development.
Issuing ratings for political parties in India? Some criteria could be:

• Avalibility and willingness to share data related to sources of funding
• Utilization of funds
• %age of funds spent on social work and community welfare
• %age of funds spent on advertising and promotion during elections and otherwise
  
• Availibility and willingness to share detailed resumes of all MPs and MLAs detailing education, work experience, and other verifiable achievements
• %age of election manifesto projects delivered as promised when the party formed goverment.
• Effect of programs (of the party's elected goverment) on key macro indices like per capita income, HDI, literacy, population, electrification penetration, etc
  

The list surely isn't comprehensive and needs more detailing.

The ratings issuing body could be certified by a non-partisan body like the election commission or so and a political party should be forced by law to display its ratings in all communication whether positive or adverse.

Surely, the idea can be developed further by the folks on jagore or others itching to "do something for the country".