I am sorry to say that your comparisons are absolutely baseless at the least if not outrightly silly and ridiculous. 'Prasar Bharti' is not a company and is an autonomous corporation of the 'Ministry of Information and Broadcasting'. It was formed with the 'sole' objective of providing autonomy to Doordarshan and All India Radio, the two Public broadcasters of India, like those in many other countries. The role of any public broadcaster is just like any other administration/service wing of the government. It's like suggesting that the External Affairs ministry ought to start making profits on issuing passports or the local municipal corporation make profits from the sewage service. It's one thing to try and recover as much of the cost from charging the customer with the sole objective of reducing the tax burden, but it is an erntirely different thing to suggest that government ought to try and make a profit from their services. In any case, the attempt to increase revenue to turn a profit, cannot and should not be at the expense of reducing services or the quaklity of those services. I suppose it would be alright as per your logic, for your local municipal corporation to decide that in an effort to reduce costs and thus profits, they shall only clean the roads and collect garbage once a month.
On the other hand, public sector companies are exactly that, companies. They exist to make a progfit and infact in most cases these were all originally private companies that the government took over in the name of national interest. In fact the very logic used to take over these private companies was that profit should not be made from certain basic essential industries and services. Thus these sectors were taken over by the government and the newly formed companies objective became to simply provide their products and services at cost and not with a motice to make, let alone maximize profits. Even with the new found zeal to make the public sector companies profitable, they are time and time again reminded of their primary 'objective' that of providing certain service/products of a certain standard and at a minimal cost to the public. As 'sud98' pointed out the most well known example is the subsidizing of petroleum products at the cost of huge losses to the public sector oil companies.
Bottom line is, one must keep in mind what the 'objective' for the very existence of Doordaarshan is, which is to provide coverage of nationally important information, news and events to the public at zero cost.