I need to choose a data type for SQL Server( BigInt vs Decimal) on the basis of performance and querying (10 digit number)
If you don't need fractions, choose bigint. In your case it will be a byte smaller:
10 digit decimal is 9 byte: https://msdn.microsoft.com/it-it/library/ms187746.aspx
bigint is 8 byte: https://msdn.microsoft.com/it-it/library/ms187745.aspx
Plus, it is faster (it has no variable part, and it is an integer type, much faster processed by cpu).
If you are only dealing with whole numbers then BIGINT will be a higher performance datatype because it won't have to deal with any rounding.
If you need decimal places you must use decimal