Hello Everyone,
I made inquiry with NCEES about FE Exam. Then, NCEES suggested me to contact state board first. If state board approves for FE exam then we can take FE Exam. Accordingly, i sent an email to Texas Board of Professinal Engineers mentioning following:
"I have completed four year engineering science in mechanical from Nepal. My degree were taught exclusively in English. I wish to apply for FE Exam. I have made correspondences with one of Foreign Educational Credential Evaluators listed on the webpage for evaluating my degree.

Do I need to provide any additional educational documents for applying the FE Exam."

In response to above query, the Texas state board replied as:
"If you have an engineering degree and live in Texas, you can register to take the FE in Texas without any other application or approval. The evaluation is not required until you apply for the EIT or PE. Registration for the October exam opens June 6.

Let me know what other questions you have.

David Howell, P.E.
Director of Licensing
Texas Board of Professional Engineers"

Thus, procedures basically, i think, depend on the State licencing board. It is worthy to make an inquiry to your State board first.