The basicdifference betweena B.Tech and Polytechnicengineeringcourses is that a B.Tech is a degree course while a Polytechnic is adiplomacourse inengineering. ... Polytechnic (Diploma Engineering) are done may be those who are not able to afford degreeengineeringand need to get into a job as early as possible.
B.Tech :In India its a professional engineering undergraduate degreeawarded after completion of 4 years of engineering study.

Diploma :Adiploma is a specific academic award usually earned in professional/vocational courses, e.g., Engineering, Pharmacy, Design, etc. Its equivalent to general degree in that discipline for example, Diploma in engineeringof Computer Science and engineeringis rated differently than Bachelor of engineeringin Computer Science and engineeringbut is equivalent to Bachelor of Science in Computer Science. It is taken soon after completing 10th.