Will it be okk ti get CIsco certification at this age? pl advice me!?
You'll be 43 either way so you might as well try something new.
As a network engineer what kind of courses required further to excel in the career?
CISCO Certification , VOIP Training and Certification , Microsoft Certification, Sun Systems Certification. There's a lot on the list.
what is ccna?can i get job after doing ccna.?
Here's the Cisco link to CCNA: Cisco is a huge company and growing. Assuming you have reasonable grades in school, or if you have some reasonable work experience, you should be able to land a job soon after getting your certification.