A "bare" Mac OS X drive has three partitions already:
While newer MacBooks may be able to boot a Bare drive off the Internet, your older MacBook needs a little more help from a Recovery_HD or a 10.6 DVD to get going.
Have you re-booted (hold down the Option key at Startup) using the Time Machine drive as the Startup Disk? If the backup was made under 10.7 or later, it should have a viable Recovery_HD that contains Disk Utility and could get you going.
You need to boot from an OS X installer disc compatible with this model's hardware or you must connect it by Target Disk Mode - Target Disk Mode - so you can re-partition and reformat the hard drive before you can install Mountain Lion on it or any other version of OS X. Here's the process:
Drive Partition and Format
1. Boot from your OS X Installer Disc. After the installer loads select your language and click on the Continue button. When the menu bar appears select Disk Utility from the Utilities menu.
If you are preparing an external or a non-startup drive, then open Disk Utility in your Utilities folder.
2. After DU loads select your hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Note the SMART status of the drive in DU's status area. If it does not say "Verified" then the drive is failing or has failed and will need replacing. SMART info will not be reported on external drives. Otherwise, click on the Partition tab in the DU main window.
3. Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Click on the Options button, set the partition scheme to GUID then click on the OK button. Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the process has completed.
4. Select the volume you just created (this is the sub-entry under the drive entry) from the left side list. Click on the Erase tab in the DU main window.
5. Set the format type to Mac OS Extended (Journaled.) Click on the Security button, check the button for Zero Data and click on OK to return to the Erase window.
6. Click on the Erase button. The format process can take up to several hours depending upon the drive size.