Abdul,
I agree with Siva Prasad Vasireddy
To elaborate his point (a little more) online SAP courses from unauthorized institutes, which means these have not SAP franchise institutes. The trainers will have generally 3 to 5 years of SAP experience and they will teach you topic by topic with screen sharing, online.
The course fee is substantially lesser than that of authorized institutes.
You can attend demos and then choose the institute to get enrolled.
SAP is difficult (and time consuming) to learn on your own.
Most important - Know what course (module) you want to learn and work in.
TW