Anton, Thank you for taking time out.
I came across one information while searching for Linux/memory usage etc.
using the command free -m while my memory usage on graph showed 90%+ I was still able to see that
as per the site linuxatemyram.com.
'To see how much ram is free to use for your applications, run free -m and look at the row that says "-/+ buffers/cache" in the column that says "free". That is your answer in megabytes:'
So my output for the above command is this.
root@****:~# free -m
             total       used       free     shared    buffers     cached
Mem:          6144       5449        694        130          0       4907
-/+ buffers/cache:        542       5601
Swap:            0          0          0
root@****:~#
So that shows 5601 Megabytes free. Hope later in future this thread will help others who might notice this with their linux systems/specially VPS etc.
Thanks a lot once again for your time taken out to help me.
As far as I can see from the screenshot, it's still using only 2% of the memory.