NDA - 188 (BJP will bag 137 of these seats)
UPA sans Lalu, Paswan & Mulayam - 182 (Congress will bag 148 of these seats)
Third Front - 130 (AIADMK front with 30 seats, Mayawati with 35 & Left with 35 seats)
Others - 43
The single largest party will be Congress. The single largest pre-poll coalition will be NDA. Pratibha Patil being a Congress nominee, will call the single largest party or the single largest post-poll combination (whatever suits the congress) to form the government.
37 of the 42 seats from Others will be willing to support UPA.
That means Post-poll UPA has 219 seats.
If UPA jettisons DMK & Mulayam, the seat count will be 174. Now add AIADMK, Mayawati & Left = 174 + 30 + 35 + 35 = 274 seats.
If Left insists that Manmohan, Pranab and Rahul are not acceptable, then Congress may prop up Sharad Pawar.
If NCP's Sharad Pawar throws in the hat then he will attract the support of UPA + Mulayam + Laloo + Naveen Patnaik + Chiranjeevi + AIADMK + JD + Left + Shiv Sena = 174 + 29 + 6 + 5 + 6 + 30 + 5 + 35 + 16 = 306.
Meanwhile, if nothing works out NDA will be called.
NDA can make it with Chandrababu, AIADMK & Mayawati. Their seat count together will be 269 seats.
Conclusion: Expect a UPA-supported coalition. Sonia will prefer Sharad Pawar over Pranab Mukherjee. So you might just see Sharad as the PM.