Hi Manali,
TestComplete does not provide any special support for direct http requests except aqHTTP object. Check documentation to figure-out if this object meets your needs.
If it does not, you may consider either pure coding approach in TestComplete or use some other tool. SoapUI, for example, is well suited for REST testing and can be integrated with TestComplete.
P.S. The link mentioned by Robert is about SOAP web services. SOAP web services are supported by TestComplete but are different from REST ones.
