Yes, you are eligible but your admission would based on your 12th exam marks with science including PCM as subjects.

Selections in most colleges are done through entrance exams such as JEE Main, JEE Advanced, BITSAT, SRMJEEE, VITEEE, SITEEE, AMUEEE, etc. These exams are conducted by different institutional bodies. JEE Main & Advanced are conducted by NTA (National Test Agency) while other entrance exams are regulated by their respective institutes.

Many private colleges also conduct direct admission on just basis of academic qualification or donation.

After qualifying for the entrance exam, candidates are allotted seats through counselling which is regulated by the respective authorities of these institutes.

You can visit the given link for more detailed information,

https://www.careers360.com/courses/b-tech-in-civil-engineering

Thank you