Question: How do I rank duplicate values uniquely also I need them in an array?

Answer:

Array formula in D2:

=COUNTIF(List, "<"&A2)+SUM(IF(A2=$A$2:A2, 1, 0)) + Ctrl + Shift + Enter copied down as far as needed.

Download excel example file.

unique-rank.xls
(Excel 97-2003 Workbook *.xls)

Functions in this article:

IF(logical_test;[value_if:true];[value_if_false])
Checks whether a condition is met, and returns one value if TRUE, and another value if FALSE

SUM(number1,[number2],)
Adds all the numbers in a range of cells

COUNTIF(range,criteria)
Counts the number of cells within a range that meet the given condition