Here are some of the colleges name with fees structure you can prefer for Interior Designing.

Aditya College of Design Studies, Mumbai- Average annual fees approximately 1.14 Lakh for Certificate.

Amity University Mumbai- fees approximately 1.26 lakh per Annum for B.DES

Kalpana International Institute of Management Studies - fees approximately 50,000  per Annum for Diploma

It also depends in which programme of Interior Desgining you are interested fees varies accordingly.