I startd installing ubuntu in my lappy......due to some reasons i just stopd installation and removed ubuntu disk from it
I love the "due to some reasons" part.
"Uhh, yeah, I made a mistake and can't fix it, but I had a good reason! No I can't tell you what it was..."
.......at that time i lost nearly 150gb i mean 150gb of space remains unallocated........i tried to merge it,to create a new volume,to delete it....but of no use......please help to recover that memory
If you don't have anything on the disk work keeping (sounds like you don't, or at least not anymore if you aborted an OS install in the midst of partitioning), then just delete all partitions and create a new one.