For the course of Bachelors in Commerce, one is eligible if and only if he/she have passed the 10+2 examination. As a result, with only the ITI certificate you can't take admission to the course of BCOM. Now if you wish you can take admission to the course of Diploma in Engineering course with the ITI certification lateral entry but its not possible for you to go for the course of BCOM just after ITI.

For more information regarding BCOM consider the link below:

https://www.careers360.com/courses/b-com-bachelor-of-commerce

I hope this helps. Wish you a great eve!