The merger, which is being touted as the largest in Indian oil and gas history, is aimed at significantly boosting the company's exploration and production business.
Reliance expects the merged entity to promote synergies in operations, higher efficiencies and lower operational expenditures.
The merger has also brought it into the league of the world's top 10 refining companies.
"This merger follows Reliance's philosophy of creating enduring value for all our stakeholders.