Hi Sumit,

The major difference between JEE Main and JEE Advanced is that a good rank in JEE Main can get you admission in NITs, CFTIs, IIITs and GFTIs while JEE Advanced ranks will give you a chance to secure a seat into IITs.

The JEE main scores are only the qualifiers for JEE Advanced Examination.

JEE Advanced is considered to be much harder than JEE Mains Examination and it is harder as some of the topics which aren't asked in JEE Mains are asked in JEE Advanced.

Refer here for more info - https://engineering.careers360.com/articles/how-jee-advanced-different-from-jee-main

Feel free to ask doubts in the Comment Section.

I hope this information helps you.

Good Luck!