Gujarat

Minimum 5 years.

Yes, I think it is not a bad decision, as both the courses are interrelated with each other and all definitely complement each other in the long run.

Go through the link below for details:
https://www.shiksha.com/b-tech/ranking/top-civil-engineering-colleges-in-Maharashtra/53-2-114-0-0
For colleges in Gujarat, filter the state in the above link.

Check out the list below for all the engineering exams across India and choose accordingly :
https://www.shiksha.com/b-tech/exams-pc-10
For Gujarat specifically, opt for GUJCET details below
https://www.shiksha.com/b-tech/exams/gujcet.

The cut-off would be announced by 10th March. However, the cut-off for the previous year was 70 percentile.

Eligibility criteria for this college is-
12th min-50%
Mandatory Subjects : Mathematics, Physics, Chemistry
Candidate must have passed 10+2 along with mandatory subjects from a recognized board/university or authority accepted by the syndicate of the Anna University as equivalent thereto are eligible to apply.
Age
Maximum 21 years
Other eligibility criteria
Candidate who have given any other examination of any other authority accepted by the syndicate of the Anna University as equivalent thereto are also eligible to apply.
For candidates belonging to SC/ST, the age limit is relaxable by three years.

Hello Shalini,
92 percentile is the border line. Generally, cut-off revolves around 94 - 95 percentile every year.
All the best.