Modi remains the favourite for PM in all of the surveys conducted primarily there's no other national leader of his stature. The Congress is as its all time low and is heavily dependent on its regional allies forming the Mahagadbandhan which unfortunately has many PM candidates which will eventually lead to infighting thereby rendering it useless.
BJP will also sustain losses and will be short of the majority alone but the NDA will still cross the 272 mark.
They might even call for an early election as the anti-incumbency is on a rise since last year.