Hello Shardul,
OData accepts Date/Time values only in that form according to the EDM.DateType specification ( JSON Format (OData Version 2.0) - Primitive Types). Most UI5 controls dealing with times and dates have an integrated conversion mechanism to handle the format.
If you have to do the conversion by your own, you can create a new Date object (e.g. new Date(2016,07,16)) and get the milliseconds value with function getTime (e.g. myDateObject.getTime() -> '1471298400000'). With that you can form the required value '/Date(1471298400000)/'.
Regards,
Florian