W4 and residential status confusion

[rahultoall]

Hi, I have recently deputed to Texas,USA for an assignment On January 26,2020 and will be leaving from USA October 30,2020. I did not fill my w4 till August and during all these days in my Paycheck the Fed tax deducted was uniform as my employer considered me as Resident alien in w4. after I updated W4 form as non resident in aug my fed tax withholding increased by 100usd.
I checked irs website and saw if I stay in USA for 183 days or more I am considered as resident alien so should I change it to resident alien in w4.
Also when filing USA returns from India what status should I put so that I can accordingly update my W4 currently