SQL Query Returning Unwanted Results
But still returns the record where resonance = ''

Select *
FROM @T1
WHERE userid LIKE '%[0-9]%'
    AND resonance not in ('DEL','Samit') 


You should define it as:

Select *
FROM @T1
WHERE userid LIKE '%[0-9]%'
    AND resonance not in ('DEL','Samit','')