CBSE 12th

For this u have to check merit of particular college. As u r a Science student so merit must be high.

Hi Disha, please seriously complete your 12th anyhow in India before making unrealistic plans like these. With 43% no university outside India will accept you and to further worsen the situation you have not even completed your 12th which is the basic requirement. There is no possibility that you can pursue your 12th abroad that too in the countries you mentioned. Study hard now and pass your board exams. You can figure out where to study and what to study after you decently pass your boards. All the best.

Eligibility criteria for this college is-
12th min-50%
Mandatory Subjects : Mathematics, Physics, Chemistry
Candidate must have passed 10+2 along with mandatory subjects from a recognized board/university or authority accepted by the syndicate of the Anna University as equivalent thereto are eligible to apply.
Age
Maximum 21 years
Other eligibility criteria
Candidate who have given any other examination of any other authority accepted by the syndicate of the Anna University as equivalent thereto are also eligible to apply.
For candidates belonging to SC/ST, the age limit is relaxable by three years.

B.Tech and BE both are same. There is a little bit difference. But I will prefer B.Tech.

Go with your studies and at the same time. Learn about software for designing 3d object and start designing
https://m.all3dp.com/1/best-free-3d-modeling-software-3d-cad-3d-design-software/
Further, design your model and keep posting on official pages of famous brands. And keep on applying for job.

IIT Delhi CS branch is one of the most demanding branch now a day, so for getting admission, you have to score top marks in IIT exam. Then only you can get admission.

No, every companies does not put the criteria of 60+ but yes, there are some.

No, you have to write E-Chat entrance exam to get admission in IIHM.