Its already there. This happened in Andhra Pradesh and there is the Andra Pradesh Prevention of Cow Slaughter and Preservation of Animals Act - 1972. So there is indeed a law.
COming to the next part, I asked you a question about why Muslims in subcontinent insist on cow when they can give a sheep as sacrifice. You have not answered it or as per my deduction,you dont have an answer.
Thirdly, true India is not the property of Hindus alone, nor is it of the Muslims. That is why I could not see the "innocence of Muslims" video or read The Satanic Verses in India. In an ideal democracy, Hindus would be able to screen the "innocence of Muslims" in theatres and watch it, read Satanic verses on a cool evening sipping a coffee and Muslims should be able to enjoy Beef korma all year long. But its not like that in India. There are certain give and takes and each community has a asocial responsibility. It is sad that some dont have that sense of social responsibility.
Lastly I know all that I said above will be ignored by your "hate india/hindu" filter and you will again jump on me. But its ok.