Expressing his angst over the alleged use of his voice for tobacco promotion, [Bachchan] posted on his blog, “Not only is this unethical and wrong, it paints me in bad light as well... For someone that does not smoke or propagate smoking or any kind of intoxicant... it is most disgusting to find someone conflagrating the law of the land.”The idea that a distinctive voice can be copyrighted seems to be a misapplication of the general principle of copyright. Copyright, like all forms of intellectual property law, is meant to protect ideas, not personal characteristics. Bachchan's voice may be distinctive, but it's not an original idea.
...Bachchan particularly voiced his concern against caricatured images that are used for commercial gain without our permission and something which he completely detested. Hence, the decision to protect his voice.
A better route for Bachchan - given that the article seems to suggest he's primarily upset about imitations or cariacatures of him - would be to argue that the advertisements that bother him violate his right of publicity or personality rights. Even in the case of parodies and cariacatures, other jurisidictions have found that personality rights still apply - for example, the famous "Vanna White case," White v. Samsung Electronics, wherein the cohost of Wheel of Fortune sued when Samsung put out a series of advertisements featuring a Vanna-like robot turning letters for a futuristic game show, and won when the Ninth Circuit Court of Appeals agreed that the ads violated her personality rights.
A brief survey of Indian case law seems to indicate that courts there seem to highly value the right to personal privacy. Bachchan would probably be better advised going this route rather than advancing a claim through copyright, which would be tenuous at best.