Hello there! 

Greetings! 

Qualifying Jee advance is not the eligibility criteria for upsc exam dear , you need a Bachelor degree to be eligible for upsc so if you qualify jee advance and then complete your engineering then you can go for upsc.

Minimum qualification for UPSC exam is given below :

• The candidate must hold a degree from Government recognized Universities or possess an equivalent qualification.
• Candidates who are in their final year or awaiting results are also eligible to appear for UPSC preliminary Examination. All such candidates who are eligible to appear for IAS exams must produce proof of having passed the said examination along with the application for the main IAS examination. 

Thankyou