Hello Chauhan, 

The GUJCET cut off for the year 2018 was as follows: 

1. Open Category ( sub cat- others) - 36292

2. Others (sub cat- TFWS)  - 10341

Since the cut off is available in the form of rank,  I cannot tell you a particular mark.  To be able to apply to GUJCET itself, you need 45% marks in your 10+2 examination. 

For other details regarding GUJCET cut offs,  check here :  https://www.google.com/amp/s/engineering.careers360.com/articles/gujcet-cutoff/amp