is it a wise choice considering u r at late 20s already?
I did mainly java in my uni days but have not touched on programming ever since i started working as a security systems engineer.
i plan to take up c# in thr meantime. will employers still able to accept me?
Although you can program many different kinds of applications, but you only possess programming skills. Looking at what you are doing now, it has more "value" than programming. Not saying being a programmer is no good. A security systems engineer can also be good in programming, because in the course of work, you will definitely need to know how some apps work. That's where your programing skills come in handy.
You also mention Java. Please, Java is a beast. There is so much you can learn , just from Java. ITs API, its security features, how its used to deploy web apps, etc. I suggest you hone your programming in Java also. Later then move on to other languages, which shall not be too much difference, except the syntax