The topic you choose must have enough depth that you can create a lot of content for it. This is important for building an authoritative site, for search engine optimization, and most importantly, for the end user. If you don't have enough content about a topic, you're not going to be taken very seriously as an authority on the topic and it's unlikely you can convince someone to make a purchase from you. 
Although this line of work is seriously threatened by automation, there are still plenty of data entry jobs available in India. It is one the simplest jobs you can do online, and requires no special skills. You just have to have a computer, Internet connection, fast typing skills, and the ability to pay attention to details. Most freelancing websites list these jobs, and you can sign up on any of them to start earning in the range of Rs 300 to Rs 1,500 per hour.
If you are more confident in your skills, you can also market directly to websites and blogs. You can contact the sites by email to market your services. That will also enable you to select the specific types of sites that you are more comfortable working with. Since there are literally thousands of websites and blogs on the web, the potential market is limitless.
2. InboxDollars – InboxDollars is similar to Swagbucks, since you’re going to be taking surveys, shopping, etc., so if you want to maximize your return, sign up with both websites. They also offer a search engine that pays you (like Swagbucks) and you get $5 just for signing up.  I won’t continue to list survey sites one after another down the list, but if you want to get paid to take surveys, also check out GlobalTestMarket, E-Poll Surveys and Survey Club.
25. Products – You can create your own product, such as an ebook or computer software. You would then use your blog as a promotion tool to get people to buy your product. As long as you create a legitimate product with a whole lot of value, you should be able to get some buyers, but like everything else with a blog, you’ll need the traffic to get the sells.