How much money India can save by managing its waste? $624 billion dollars per annum by 2050. With the implementation of circular economy. Read report here: https://www.ellenmacarthurfoundation.org/assets/downloads/publications/Circular-economy-in-India_5-Dec_2016.pdf
Can we ever manage the waste (domestic, plastic, medical and varieties)? Yes, It is possible to do it. It is through reusing, buying things for long term, buying only the things that are required, donating / selling the things that you do not need instead of throwing in garbage. Understanding that the garbage is not the endpoint, but a starting point.
Ocean plastics, is there one companies actively working on it at scale? TheOceanCleanup has taken the task of aggregating the plastic waste from the oceans.