Manish to excel in interior designing you will need to do 2-3 years among different course of available in various colleges. some of the top fashion designing colleges in India are:

• National Institute of Design, Ahmedabad
• CEPT University, Gujarat
• Arch Academy of Design, Jaipur
• JJ School of Arts
• College of Architecture
• Exterior Interiors Pvt Ltd
• Pearl Academy
• Vogue Institute of Fashion Technology
• Sai School of Interior Design

To know more about the programmes and courses offered by these colleges you can go through this link: https://www.shiksha.com/articles/top-10-interior-design-schools-in-india-blogId-10599

Feel free to ask if you have any more queries. All the best!!