B.Tech in South Korea

First of all, you have to take admission in those college which provides the study exchange programme with the foreign countries if you want to study at low cost
This is one of the best options to study in South Korea
As from my understanding you should take admission in these colleges.

Hi Jisna,
You can pursue your Bachelor's degree program in engineering in South Korea. Please note that JEE exam score is not required but you must have good academic grades. You must also take the IELTS to meet the English proficiency test. You can check The Korean Government Scholarship Program which covers the full expense. For more details see here:
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https://studyabroad.shiksha.com/south-korea/be-btech-colleges-dc