Given the accuracy of some of the messages cited by the report, the regulator, Sebi, should definitely take cognizance of the situation and carry out an investigation. If it does discover that any of these messages originated from insiders, Sebi has the power to hand out prison sentences, or fines, or both.
More broadly, Sebi should try to create means of observing this medium and others like it. While Whatsapp is the most popular of the encrypted instant message platforms, there are several others like it. Other market regulators such as America's SEC also have to deal with the issue of price-sensitive information being passed through such mediums.