Jharkhand

It will take 4 years.

No, as you said that you are already pursuing, you don't need to give any entrance exam.

Of course, you can apply for JCECE. No matter from where you have passed your class 12th. But, when you are filling form of JCECE, you have to mention about your domicile state.

You can get some help on this link:
https://iitism.ac.in/index.php/placement#phomem.

1. Indian School of Films and Drama (ISFD),
2. Dadasaheb Phalke Acting and Film Academy
3. Jharkhand Film and Theater Academy
4. Zee Institute of Creative Art
You can find more excellent acting schools in Mumbai, Delhi etc.

Among all of these colleges, BIT Dhanbad is best for M.Tech. It is ranked among the top of the colleges in India.

In Eastern India, IEM Kolkata is best for BCA. In 2018, IEM has generated 223 offer letters for only 100 students. 23 students got 1 job offer, 31 students got 2 job offers, 14 students got 3 job offers, 12 students got 4 job offers, 6 students got 5 job offers, 3 students got 6 job offers.

Teaching and facility wise, XISS, Ranchi is a better option for HRM. But, XIME-Bangalore has better exposure because of the location of the college and plenty of opportunities.

You can consider Career Launcher.

Yes, you can enroll in B.Tech programs pan India under Lateral Entry programme. But doing B.Tech from West Bengal would be a good choice instead of Jharkhand.