How to get Clear Quest Defects data with out native client on the machine. I can login via web client.

Hi Pavan,
This is RTC forum. To ask CQ question, you should ask it on DW answers: https://developer.ibm.com/answers/

If your original solution is based on Internet Explorer, then you are accessing the ClearQuest Web. If you try to remove the dependency of Internet Explorer, you need to implement the HTTP request and response processing in your C# code. In this case, the ClearQuest native client is never involved.

If your original solution is based the ClearQuest COM component, then it is a different story. In this case, you need to implement a completely different solution which should be based on ClearQuest OSLC REST API.
http://www-01.ibm.com/support/knowledgecenter/SSSH5A_8.0.0/com.ibm.rational.clearquest.oslc_cmrest_api.doc/topics/c_cq_oslc_rest_api_ovw.htm