Class 11

Class 11th standard result is not so important. It is just like a practice test for class 12th.

You can apply it after 12th. Yes, you can pursue hotel management or be eligible for NCHMCT-JEE if your steam is arts. It is just that, you need to start preparing for the exams. Better results in the entrance exams will give you better college.

Hi Anushri,
To study B.Tech in USA, you must take the SAT or the ACT. You must also take the TOEFL. These are the application requirements. The cost will depend on from university to university. USA is expensive. Check here for a better idea:
https://studyabroad.shiksha.com/usa/be-btech-colleges-dc
You should also start checking university websites and also check the common app portal, this is the portal by which you have to apply to US universities.

Yes, you can apply for NCHMCT JEE 2018.

Students from class 11th will not be allowed to appear for the NEET UG examination.
Students who will be appearing in class 12 board examinations or whose result is awaited are eligible to appear for NEET 2018.
NEET Eligibility Criteria 2018 - age criteria
According to the NEET 2018 eligibility criteria, a candidate has to complete 17 years of age either at the time of admissions or else on or before December 31, 2018. Hope this helps. Regards.