I have Samsung Galaxy Pocket - GT-S5300.
Is there a way to install ICS and it will work properly? Will overclock be needed?
If so, how to do so?
This device will never officially get ICS, as it only has an Armv6 processor. ICS needs an armv7 processor to function.
The only way to get ICS would be if someone ports it to your device - but it would be difficult. I suggest you look at XDA-Developers to see if someone has ported it, or is trying to.
Be aware that it would be buggy if it is ported.