The institute has about 200 scientists (more than half of them hold doctoral degree) and 100 technical support staff. The major research areas include the four traditional branches of oceanography - biological, chemical, geological/geophysical, and physical - and some other areas such as marine instrumentation and archaeology. The institute has well equipped laboratories to conduct research in these and multidisciplinary areas. The institute also operates a coastal research vessel CRV Sagar Sukti, a 23 m vessel equipped for multidisciplinary oceanographic observations. NIO's scientists also have access to the ocean going research vessel ORV Sagar Kanya, operated by the Ministry of Earth Sciences. The institute has a library with 15,000 books and 20,000 back volumes of research journals, making it the best collection of printed literature on ocean sciences in the country.

In addition to basic research, the institute also carries out applied research sponsored by the industry. These studies include oceanographic data collection, environmental impact assessment, and modeling to predict environmental impact. The institute also provides consultancy on a number of issues including marine environmental protection and coastal zone regulations.

With the largest collection of ocean scientists in the country, and equipped with suitable ocean research infrastructure, NIO serves as an advanced center of education in ocean sciences. Many universities have recognized the institute for carrying out doctoral research, and a number of NIO scientists have been recognized as doctoral research guides. There are at present over 60 Junior/Senior Research Fellows (qualified through CSIR/UGC eligibility criterion) pursuing their doctoral studies in the institute. In addition, over 240 undergraduate and postgraduate students pursue their project research at this institute every year. About 5% of them come from foreign countries.