As you want to get the list of some of the best courses which are available after getting failed in 12th class so here is the information of the same for you:

You can do polytechnic course in various branch as Electrical, Mechanical , Civil, Electronics , Computer , IT

And ITI course in Electrical, Mechanical, Civil, Diesel Mechanic

And computer course DCA (DIPLOMA IN COMPUTER APPLICATION)
Computer Hardware and Networking

You can also do the fashion designer, interior design course