Is it really compulsory to take science in order to join IIT ? CAN'T I take diploma in information technology?What is difference between IIT and diploma in information technology ?

dear student 
they are diffrent , after diploma also , you can join engg btech branch in lateral engg . catagory . 
so, there are diffrence in course and syllabus of btech and diploma . 
and yes , its compulsory to take science in order to join iit for btech through jee mains . 
hope it clears