I'm an IT lecturer at NYP and I can advise on IT courses. There are almost no drawings required for IT courses. If the student is good at logical thinking (eg good at maths), he/she should be suitable to do IT.
As for theoretical modules, it depends on which diploma you choose. Generally, the more technical IT diplomas (e.g. Diploma in Information Technology) has few theoretical modules as compared to the diplomas that have some business components in it (e.g. Diploma in Business Informatics).
Hope I've cleared some of your doubts. If you would like to find out more, you can reply to this post or drop me an email at email@example.com.
Engineering and IT Courses in Poly
Is there life after O/A-Levels? Definitely! How well a person does in tertiary education is correlated with job opportunities open to the person. Discuss issues pertaining to nstitutes of higher learning here.