Hello friends;
Can anybody help me in designing the snubber protection for the IGBT?
I'm using 1200 V, 400 A, IGBT in buck converter mode with 100 V,250 Amp DC Pulsed load and 3 to 10 KHz frequency.And Can I use inductor for di/dt protection of IGBT?
Please reply soon:)

You have some specific modules available for use as snubbers for IGBT's. I would think that lead length is extremely important, so it makes sense to use a packaged product.

Cornell Dubilier (CDE) Low Inductance IGBT Snubbers - TTI, Inc. (Authorized Distributor)