Yes you can apply for many reputed government job exams or BSNL JTO Post after passing B tech 4 year examination .

BSNL JTO-Telecom
You have to passed Bachelor of Engineering/Bachelor of Technology or equivalent Engineering degree in any of the following disciplines from a recognized engineering college/university.

i. Telecommunication,
ii. Electronics,
iii. Radio,
iv. Computer,
v. Electrical.
vi. Information Technology

Age Criteria:
The maximum age for JTO exam is 30 years.
Age relaxation is provide for SC/ST/OBC category as per govt rule.
Nationality:
Only Indian Citizen are applicable.

Or you can apply for following job exams :
IES
IPS
IAS
Civil service exam
CDS exam
SSC CGL
Railway exams
Bank exams