If you are good at writing and can easily express your thought in writing, then you can write your hobbies, interests, and passions, and publish them as a blog. Soon you can become a well-known blogger if your writings are suitable and beneficial for the visitors. You can create your blog at WordPress with no investment or you can use a self-hosted paid blog.
In the case of a self-hosted blog, you may have to invest as little as Rs 100 per month initially for hosting the domain. You may initially get the domain free for one year. The advantage here is that you can easily custom your site as per your requirement. You can monetize the blog through advertisement, product reviews, affiliate marketing and so. Remember, earning through blogging is time taking and may take more than a year or so. If you want to become millionaires by over-night, then you may not think to write a blog.