Polytechnic

Why do you want to go for Diploma and Degree both . that too at the same time.
The Polytechnic is a Full time Three Year Course where you have arround 10-12 subjects,
Practicals,Submissions and so on . and its a 12- 15Hrs Affair on daily basis and the same is with the Degree course. Do you think you can handel it ?
After completion of the Diploma Course you are eligible to get into 2nd Yrs of BE / Degree course. and I thik this can only serve your desire to complete both.

Hi Sudeep,
Diploma Courses in Agro-Polytechnic are offered in four disciplines - Agriculture Science, Horticulture Science, Animal Science and Fishery Science with following objectives:(1) To develop skilled personnel in certain specialized fields(2) Capacity building of the personnel for their self-employment
You must have completed your 12th Sc with a minimum of 50% and 40% in case of SC/ST/PH.

Every college offers seat via Lateral Entrance Eligibility Test (LEET). You have to appear for it and should get a seat in it.
Also, states conduct their respective common entrance test for Diploma people.

Yes, you can!
Part time B.Tech means AMIE.
But it's quiet difficult.
Never bother it's difficulty and keep rocking!
Coming about institutes offering AMIE, it depends upon your region.
Hope this helps.

Based on your subjects, B.Tech ECE is the based option for you. In case you are unable to get admission in B.Tech ECE then B.Sc CS is also a good option.

Hi Danbeer,
You cannot take admission in IITs after completing polytechnic as you will need to require to attempt for JEE Mains exam. You can only sit for JEE exam after completing class 12th. So, I am afraid you can only have a chance to get into IITs for Masters after completing B.Tech through lateral entry admission.
All the best.

You can take admission in Diploma in engineering based on your 10th class results. On completion of Diploma in engineering, you are eligible to seek lateral entry admission in B.Tech second year.