Most 'Free' topups are DBR topups. It will deduct money on daily basis and may have lock-in period.
Re.1 Topups are Sunday Sale topups that is valid for 30 days after which it will be charged DBR.
Only following topups are actually free.
Toonami pre-suspension
Star Sports 2 in Myplan 99 pack
NewsX free
Media One Free
Telugu FOC
Ten 1 Free
Janam Free