I installed Nitdroid on my N900 long time ago. Yesterday, i wanted to clean Nitdroid by deleting it's partition but i deleted home partition instead. And when i realised that i has just done a terrible mistake, i tried flashing N900 several times through flasher 3.5 and stuck at this.



Any idea I really need your help now

http://wiki.maemo.org/Updating_the_tablet_firmware

I am not sure, if this applies: as you installed NITDROID.

However, in addition to general flashing guide on the wiki, I had to re-flash my whole device recently as well:
[HOWTO] FLASH N900 Fremantle / Use rescueOS to Backup MyDOCS / locate FIRMWARE RX-51 files and flasher

(NOTE - first try to rescue data, at the end this flashing process sets the device to an empty state)

Before, though, I could rescue some data using the rescueOS - I described the steps how I did this as well in the guide.

If you deleted all of home, there might be nothing left. You might still be able to get some data back, if you copy the whole device as an image and apply some undelete/data recovery tools: Tools: Data_Recovery

I downloaded and flashed a combined fiasco image and everything is fine now
thank all of you for replying