now BANKNIFTY08FEB1826300CE is ok . BANKNIFTY08FEB1826200CE is having issue. Please create an SOP for your production config team to create the complete option chain instrument list .
I think in both above cases it was not traded hence you didn't get the quote. Now, you can get the quote for BANKNIFTY08FEB1826200CE because it is traded after you posted this issue.
Now, you can get the quote for BANKNIFTY08FEB1826200CE because it is traded after you posted this issue.