The salaries of a Hadoop developer differs with experience and the companies. The average salary of a Hadoop developer in India is around ₹7LPA. For an entry-level, Hadoop developer can get 4LPA and having an experience of 2+ years may get you at least ₹12LPA. According to Glassdoor, 5765 job postings for Hadoop developers last month alone in India.
If you are interested to become Hadoop developer, I suggest this course of Hadoop Certification by Intellipaat.
You can watch this video on Hadoop developer to know how to become a Big Data Hadoop developer: