WHAT IS NID? 

NID stands for National Institute of design, is nationally as well as internationally one of the finest educational and research institution which provide Industrial, Communication, Textile and IT Integrated Design courses both for under-graduates and post-graduates and doctoral levels.
National Institute for design is the first design Institute in India established by Indian government, Ford Foundation and the Sarabhai family  in the year 1961 at Ahmedabad. It was an autonomous all-India body. NID has been ranked as India’s No. 1 Design Institute. National Institute of Design has it’s total 7 campus all over India, such as, Ahmedabad, Bangalore, Gandhinagar, Andhra Pradesh, Madhya Pradesh, Haryana, Assam.

NID DAT 

NID conduct an entrance examination called NID DAT which is a design aptitude test every year to take admission in B. Des and M. Des courses at NID. Candidates, willing to pursue design courses, must apply for NID DAT to get admission at NID. NID DAT is divided in to two different parts: NID prelims and NID Mains.
NID Prelims which is the written part whereas NID mains is the part where candidates have to go for studio test and personal interview. 

Process to register for NID DAT studio test. 

To register for NID studio test which is the part of NID mains, First of all you have to register for NID DAT and crack it with eligible score. 

APPLICATION FOR NID DAT STUDIO TEST

Step1. Go to official site of NID and register yourself. 
Step2. Login in to that site with your own ID password
Step3. Fill up the application form with required documents 
Step4. Pay the application fees online with debit card, credit card or UPI or others given option
Step5. Submit the form
Step6. Download and take a print out of the form. 
Step7. Wait for the important dates related to the exam
Step8. Download the admit card, which works as an hall ticket of the exam. 
Step9. Sit for NID Prelims written part and wait fir the result. 
Step10. Qualifying in prelims will make you eligible for mains studio test. 
Step11. Download admit card fir NID mains. 

Now you are eligible for NID mains first part, studio test round. 

NID DAT APPLICATION FORM REQUIRE:

• Photograph (JPG/JPEG; not more than 100kb) 
• Signature of candidates (JPG/JPEG; not more than 100kb)
• Educational qualification details, communication details, etc
• OBC-NCL certificate/ST certificate/SC certificate/EWS and disability certificate (it applied for general, general-EWS, OBC-NCL, ST/SC- PwD candidates) (JPG/JPEG; not more than 150kb) 
• Copy of the first and last page of the passport only for overseas candidates (JPG; not more than 150kb) 
• Candidates have to pay the NID DAT application fee via online through net banking/credit card/debit.

This is how you can sit for NID studio test. 

see how to prepare for NID studio test, 

https://designfresher.com/forum/question/how-do-i-start-preparing-for-nid-studio-test-entrance-exam