Information Technology act under section 66A that prescribe penalty for sending offensive or abusive messages through the means of communication services etc. This act is broadly accepted by lawyers and legal academics to be unconstitutional.
According to Act 66A IT Amendment, 2008 following will be punishable with imprisonment that may extend to three years and fine:
(a) any data with grossly offensive or menacing character;
(b) any data for the purpose of causing harassment, troublesomeness, hazard, obstacle, insult, harm, criminal intimidation, enmity, horror, or ill will, firmly by making use of such computer resource or a communication device,
(c) any e-mail or electronic mail message for the purpose of causing annoyance or inconvenience or to deceive or to mislead the addressee or recipient about the origin of such messages.
For more details you can login to http://cis-india.org/internet-governance/blog/breaking-down-section-66-a-of-the-it-act