I am considering getting a civil engineering degree in Thapar University and a computer science degree in Galgotias University. So which one should I prefer? And how are these colleges?

Thapar University is better than Galgotias University for studying. Here in the following table, you will get basic information about both universities:

• Galgotias University was established later than Thapar University. Thapar University also has a name in industries that will help you in placement. The education quality and level of Galgotias University are not better when compared to Thapar University. 
• Thapar University has a legacy of over 60 years. It has a highly successful alumni base. The faculty base for Civil Engineering at Thapar is one of the best. A lot of companies come for campus placement at Thapar. 

If you are genuinely interested in CS then go for Galgotias. However, if you make a comparison between Galgotias University and Thapar University, then the latter is a better option than the former in terms of quality of education, environment, and placement.