Agree with tsk, take NH17 along the coast to Bombay and proceed to Delhi via Gujarat and rajasthan. Great roads and lots of options to break.
My suggestion would be somewhat similar to tsk.
But you have to be very fast, and if you do a bit of night driving, you can quicken your trip by, say, cutting 1 day.
Distance will be TVM-Bombay 1,750 kms, Bombay-Delhi 1,450 kms, Delhi-Shimla 400 kms
Kumar |