Closing old cc will impact my cibil ?

[katana2016]

Hello Guys,

Right now I'm using 4 CC
1) Flipkart Axis 36months old [Joining ~500 ]
2) HDFC millennia 36months old [Joining ~1k]
3) SBI Cash back 32months old [Joining ~1k]
4) ICICI Sapphiro 18months old [LTF]

from past 2 year all these cards got devaluated.
I wanna upgrade my cc wallet like 1 premium card + 3dummy card [with less annual fee]
So I checked the best cards from Axis, HDFC& ICICI, after the comparision between Axis atlas,ICICI Emerald normal [eligibiled] & need to check from HDFC which

Please let me know if any suggestions
I decided to go with Axis atlas based on Joining vs reward structure compared to ICICI Emerald

I don't wanna increase the count of my cc
So,
1) Can I upgarde from Flipkart Axis to Axis atlas ?
if this doesn't work shall I close Flipkart Axis and then apply for Axis atlas? will it impact on credit score ?
2) Will they allow to downgrade the HDFC millennia to some basic cc which doesn't have any annual fee but should work on flipkart and amazon sales ?

My monthly exp will be 50k to 1L