Hey Omkar,
IT sector is generally related to the design, implementation and management of information in Engineering while Core sector is related to Production and construction. Generally Mechanical , Civil and Electrical Engineering is come under the core sector of Engineering. While CS, IT & ECE is not related to core sector.
Hope this information will help you. Best wishes for career.
Thank you
Regards
Vikash Pal Jadaun

It sector comes..likes... software jobs
Departments like Cse ECE will come under IT
Nd core include mechanical, electrical,civil etc

Dear Omkar,

Greetings.

Information Technology branch consists of topics related to Information management (storage and retrieving) , Information security, Software engineering, Computer Science, web scripting etc. In short, it is aimed at training students to become Information management experts and put their skills to support various Industries and spheres of life.
Whereas,

Core Branch is a term used for the basic engineering branches and hence the others were derived from them according to demand in market considering every sector.
For example you can call Electronics, Computer Science, Electrical, Mechanical, Civil, Chemical as some of the core branches.

I hope this helps!
Let me know if you want to have more information.

Thank you.

Information technology (IT) is the application of computers to store, study, retrieve, transmit and manipulate data, or information, often in the context of a business or other enterprise. IT is considered a subset of information and communicationstechnology (ICT). ... We shall call it information technology (IT).

CS,IT is not the core branch of engineering but the core branch is the mechanical ,electrical.