Dear friend,,,
There are various colleges which has diploma course in interior designing. NID is one of the most popular college offering diploma course in interior designing.

NID (National Institute of Design)conducts entrance exam every year on the national level for admission of students in theUndergraduate and Postgraduate courses. Students are shortlisted on the basis of their performance in theDesign Aptitude Test. The DAT isa two-stage examwithPrelims and Mains.
How To Apply

A candidate should visit the official website of the NID.A candidate should getregisteredby giving his/her basic details, like Name, Phone number, and Email id.Upon registration,login credentialsare sent to the candidates personal email id.
With login credentials, a candidate will be able to access the application form.He/ she should fill allspecified columnsin the application form.
Along with the application form, a candidate should upload the scanned copies of the Photograph and Signature.
The filled application form should be submitted along with the application fee.A candidate can pay the application fee throughNet Banking,Credit Card or Debit Card.
Give the entrance exam of NID for the diploma course .
Hope this may help u .
Good luck !!!