do i need to write hcu entrance exam if u already wrote jee mains? can i get seat through jee mains in hcu?

Hyderabad University was established in 1974. It offers various Postgraduate courses including five-Year Integrated Master’s Degree in the field of Science, Medical Science, Life Science, Performing Arts, Management, Social Science, Humanities and Engineering. It also offers M. Phil & Ph.D. courses in the various discipline at Doctoral Level. The application form can be filled online by visiting the official website.

Since in your question i cannot properly get what you are actually looking for like course and all.

as you have mention about JEE Main in your question, i could assume that you are looking for Engineering Courses.  I hope below mentioned points would help you out:

• Integrated MTech (Computer Science) admission is based on the score in JEE Main followed by counseling JOSSA.
• GATE qualified candidates can apply for admission to MTech program. Hyderabad University will conduct a Written Test and Interview for the shortlisted candidates.
• Students can also apply for Integrated MTech (Computer Science) on the basis of score in JEE Main.
• The University also provides reservation to SC/ST/OBC/PWD and Wards/ dependents of Defense Personals and Kashmiri Migrants.

For rest of information, it is suggested you visit the official website of Hyderabad University.