Hello Yash

Few core subjects of Diploma in civil engineering are:

• Building and construction
• Maintenence engineering
• Drawing
• Transpiration engineering

Other subjects are

• Applied mathematics
• Noise control
• Building material
• Building Acoustics
• Project management

Diploma in Civil engineering also  include

• Attention to detail
• Technical skills
• Analytical thinking
• Quantitative aptitude
• Hard work
• Creativity

For detailed information you must refer the link given below

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