is it hard to take admissions in USA universities than to take admissions in Indian universities or IITs?

Nothing is hard, the exam pattern for both are very different. For taking admissions in IIT's you have to gain sound knowledge in the subjects of pre-qualifying exams. While for studying in USA you have to be very much strong in english(read, listen, write) as well as in your aptitude. Yeah its fact

Admission in good universities is not as difficult as taking admission in IITs or IIMs but more difficult compared to normal Indian universities.