IF WE GET ALLOCATED A SEAT THROUGH FIRST COUNSELLING, CAN'T WE CHANGE IT IN SECOND COUNSELLING?

I got 2 seats ,one through TNEA counselling and another through JOSAA. Which is best MIT chennai ECE or NIT trichy EEE ?

I got 98.2 percentile in session1 2022. Which is the option for me? Can I get NIT with this? Also if I consider a private college, which is better: MIT manipal or LNMIIT jaipur

1a) The binding energy of a calcium 2p electron is -349.7 eV. What would be the effective nuclear charge experienced by a calcium 2p electron? (RH = 13.6 eV)

 

BITS Pilani for cs or IIIT Hyderabad or dtu considering I am a delhite