Getting into a diploma course varies from the course you wish to pursue and from where you wish to pursue it from. The admission is conducted by the university itself and every course has its own eligibility criteria, however the base line remains same i.e.
Students who wish to get admission for Diploma in IT course must have completed higher secondary or 10th standard. They should have secured a good percentage so that this diploma course becomes easy. Students can also go for this course after their 10 + 2 or senior secondary level of education.
Now, if you have a particular course in mind and where you wish to pursue it from please do comment along with your educational qualifications, age. So we can provide an accurate answer.