Hi Rudra! The days you required to get prepare for UID DAT is completely depend on you. Here is the syllabus and exam pattern for you. Generally UID exams are easy. You just need to practice drawing and polish your creativity skills regularly. And have to practice lots of general aptitudes, mathematics, reasoning and General knowledge for the written part. How many days should be needed basically depends on your skills and how many days you have left for the exam.
UID organise their own entrance examination, which is call UID DAT. DAT here stands for design aptitude test. UID DAT is to take admission of students who are willing to pursue UG, PG and PhD courses from UID.
UID DAT is a written test with the duration of 3 hours. This is a test to examine candidate's Design aptitude skills. This written paper will consist multiple choice type questions and subjective questions.
After clearing DAT candidates have to appear for 2 more rounds which are: situation test and portfolio evaluation.
Hope all these information will help you Rudra to know about how many days you must needed to get prepare for UID DAT! you have left around 2 months for the exam approximately. If you didn't start yet, start immediately!!