Hello student student Gate syllabus for civil en gineering are mentioned below -

1)Genral aptitude

2)Engineering mathematics

3)Structural Engineering

4)Environmental Engineering

5)Transportation  engineering

6)Geo technical engineering

7)water resources engineering

8)geomatics engineering.

For more updates refer to the link mentioned below

https://www.google.com/amp/s/engineering.careers360.com/articles/gate-syllabus-for-civil-engineering/amp

Feel free to comment if you have any doubt

Good luck