Dear Vandana ,

Generally in GUJCET hall ticket , Roll number is same as the Seat no that you can find at the left corner of the hall ticket , under the candidate's name ! You can get your hall ticket from your school or can download from the official website of GUJCET .

Don't worry , after reaching examination venue , the invigilators also  will guide you to predict your seat no / roll no.

Hope this information helps !

All the best !!