To test a date falls within a specified range, you can construct a DateTime object and assert that its within a 2 set DateTime ranges:
var start = DateTime.ParseExact("15-10-2017", "dd-mm-yyyy", System.Globalization.CultureInfo.InvariantCulture);
var end = DateTime.ParseExact("15-11-2017", "dd-mm-yyyy", System.Globalization.CultureInfo.InvariantCulture);
var dateFromtable = DateTime.ParseExact([DATE_FROM_TABLE], "dd-mm-yyyy", System.Globalization.CultureInfo.InvariantCulture);
Assert.That(dateFromtable >= start && dateFromtable < end, Is.True);
To test your % a simple int cast and check similar to the date assert above.
Your Month check can be done in many different ways, the simplest most straight forward i believe would be to construct a list that contains acceptable months
var acceptableMonths = new[] {"Jan", "Feb", "Mar", "Apr", "May"}; //Assuming may is included in the list
Assert.That(acceptableMonths.Contains([MONTH_READ_FROM_TABLE]), Is.True)