Should the NDA government be worried about the no-confidence motion against it?

No.

This is showmanship, not news. Even as proceedings in the Lok Sabha are stalled due to the incessant arguing between parties, a no-confidence motion against the government would fail if it were raised. In the 539 member house, the BJP currently has 275 seats excluding those belonging it to its allies. This assures it of the support needed to defeat the motion.