i'm kartik i'm doing b.tech in E.C , i want to know that , is CCNA good for me after b.tech,

hi.... i'm kartik, i have done diploma in electronics & communication , now doing b.tech in same, i want to know that, is CCNA good for me after b.tech, and which ccna is good (voice,security,wireless) and i heard that CCNA certificate is valid for three year ... is this true...??