You need not respond immediately to the outstanding demand. Wait for 1 month. Generally, The portal will nullify itself. If it doesn't, then yes respond as disagree and provide them reason as challan paid and has CIN. And submit the details.
Shri.Doshi Sir & Shri.Chhugani Sir ,thanks for your valuable prompt reply, Today my deposited assessment tax reflected on 26 AS. And from yesterday on IT portal dashboard "Demand Estimated: text. nill" written in place where dept. shows refund amount earlier.
On dashboard there is no any demand of outstanding tax
Thanks again, want your valued opinion and guidance in future