A day after inking the deal for the biggest special economic zone (SEZ) in the country in Haryana, an official release issued by Reliance Industries today said its two proposed SEZs in Mumbai would contribute Rs 50,000 crore to the country's exports once they are operational.The SEZs, to be set up with an initial investment of Rs 25,000 crore, is expected to attract investments of Rs 2,50,000 crore over the next decade and create employment opportunities for 25 lakh people, the statement said."The SEZs known as Navi Mumbai SEZ and Mahamumbai SEZ would attract capital investment of Rs 25,000 crore, which, as per primary expectations, is likely to touch Rs 2,50,000 crore over a decade," the statement added.