NTA doesn't communicate with Candidates through offline mode. All types of Communication are through Registered email and mobile number. So even if you have updated Delhi as Mailing address but you hold the domicile of West Bengal, you can certainly participate in West Bengal State Counselling in which 85% of the State Government Medical College seats and Private Medical Colleges are filled. You can check the domicile criteria at: https://wbmcc.nic.in/pg/ShowPdf.aspx?Type=B51A60734DA64BE0E618BACBEA2865A8A7DCD669&ID=B1D5781111D84F7B3FE45A0852E59758CD7A87E5#:~:text=In%20the%20District%20of%20under,on%2031%2D12%2D2019.&text=has%20passed%20the%20'10%2B2,in%202020%20from%20this%20Institution .But to give you an idea,

1. You need to be residing in West Bengal continuously for the last years as on Dec 31st, 2019

2. Or your parents should have been permanent residents of West Bengal with permanent address within the State of West Bengal.

The proforma for domicile certificate for both the conditions is different and you can check that in the link provided in this answer.