The students from any branch such as Science, Arts, Commerce, Humanities and more will be eligible for the NID DAT exam. hope you know that there were two exams to be qualified to grab a seat under NID. i.e Prelims and main exam. basically this both exams contains the a lot about the designing,visual viewing,shadows views,Visual logic .etc so all this is related to the most designing part and the one who is more interested to have a seat must have a lot of practice about the lot of the designing part.
While you are studying the class 12 , you can start your preparation in the class 12 only. if you are not going with the jee main or engineering path you can surely set a path to the NID. after your college hours make a schedule or tution for the NID syllabus and maintain both equally. the application for NID will open in the month of october and exam will be in the end of december so you have plenty of the time after your class 12, while in the class 12 go with the whole basic concepts and after class 12 completion you can passiontely go with depeer study to crack a seat.