how do I get everything back to normal (partition issue) Okay, so I've recently shifted to Mac from Windows. I was curious to check out what the Yosemite OS looked like, and hence I downloaded the beta and had it up and running. It was downloaded on the primary hd. 

There were already a few backups on my time machine, so I decided to erase the primary macintosh hd and restore the backups. Everything got erased and it's all lying as a corestorage unit now. It says that there is no available space and all the options have been greyed out. I don't know how to create the partitions now and all efforts are in vain. Any help would be appreciated.
Try using cmd + R during startup and booting to the Recovery HD.  

Booting to Recovery HD.

Open up DiskUtility from the menu and you should be able to access the drives and re-partition them and restore the OS again.