Can I get admission in computer courses in NIIT institution after passing 11th grad examination ?

Yes, you should join in NIIT. NIIT Limited is a global talent development company was established in 1981.
NIIT is the world's largest Information Technology training and education company.

After 11th or in 11th you can apply for NIIT computer course.

NIIT offers following Computer Course:
Basic Computer Courses
NIIT’s ‘Swift’ programs

you can do some basic computer courses such as
GNIIT,
ANIIT,
G2EE,
Ciso,
Java,
Oracle,
C,
C++ etc.....

Other courses :
NIIT offered following of courses:
1. GNIIT (Software Engineering)
2. GNIIT (Systems Engineering and Networking)
3. GNIIT (Business System & Information Management)
4. GNIIT (Information Systems Management)

Fee: (Tentative)
Here you are looking for Fee of NIIT courses:
1. GNIIT (Software Engineering) program fee is 137000.00 for 3 years.
2. GNIIT (Systems Engineering and Networking) program fee is 42500.00 for 3 years.
3. GNIIT (Business System & Information Management) program fee is 117000.00 for 3 years.
4. GNIIT (Information Systems Management) program fee is 96500.00 for 3 years.

Contact detail:
Corporate Office:
NIIT Limited
85, Sector 32, Institutional
Gurgaon 122001
India
Tel: +91 (124) 4293000
Fax: +91 (124) 4293333