IDC School of Design at IIT Bombay is located at Powai, which is an eastern suburb in the North-Eastern part of Mumbai.

Public Transport 
Mumbai has a reliable public transport networked by Mumbai Suburban Railway, BEST Buses, Taxis and Auto rickshaws (Auto rickshaws, however do not ply further south than Sion and Bandra). 
The nearest suburban railway stations to IIT on the Central line (connecting CST, Dadar, Kurla, Thane, Kalyan) are Vikhroli and Kanjurmarg stations. The nearest station to IIT on the Western line (connecting Church-gate, Mumbai Central, Dadar, Bandra, Andheri, Borivli) is Andheri.

Suburban Railway Transport:
From CST Station/Dadar:
Take a slow train on the Central line to Thane/Kalyan/Karjat. Get down at Vikhroli or Kanjurmarg station. Take an auto to IIT, Powai (fare up to Rs 20). Enter the campus from the Market gate (the first gate you come across). Drive straight in to reach IDC.

From Mumbai Central/Church-gate:
Take a fast or slow train on the Western line to Andheri/Borivli/Virar. Get down at Andheri Station and come towards the East side of the station. Take bus or auto (fare up to Rs 100) or taxi (fare up to Rs 250) to IIT, Powai . Enter the campus from the Main gate (the first gate you come across). Drive in to reach IDC via other departments.

Alternatively, you can get down at Dadar station and change platform to the central line. Take a slow train on the line to Thane/Kalyan/Karjat. Get down at Vikhroli or Kanjurmarg station. Take an auto to IIT, Powai (fare upto Rs 20). Enter the campus from the Market gate (the first gate you come across). Drive straight in to reach IDC.

If you come by Air:
International flights land at Sahar Airport which is about 8 kms from IIT. The Domestic Airport- at SantaCruz is about 12 kms. Its' best to take a Pre-paid taxi (costs about Rs 350 - 500 (US $ 8.00 -12.00) from Airport to IIT Bombay, Powai) available at the Airport to come to IIT. Auto rickshaws and regular taxis are also available at both the airports for reaching IDC at IIT, Powai.