can any one send me the query to find the number of rows for a particular column,
You have a terminology problem here, so it's hard to understand the question.
Rows aren't parts of table columns; rows are parts of tables.
Perhaps you mean one of these?
select count(Column) from Table
select count(distinct Column) from Table
Post some example data and the result you'd want for that example.
Solutions are easy. Understanding the problem, now, that's the hard part.