Can we merge two cells of two different rows while designing a report in SSRS???
I don't think so, SSRS will process rows sequentialy.
Your best bet would be to create a view or a temporary table and then create a report using that as the source.
No, you cant. What you can, is mimic this with absolute positioned text field. The problem with such text fields is that not all exports works correctly.
It depends on the version of SSRS you are using. You can only merge across columns in SQL Server 2005. But with SQL Server 2008 you can merge across columns and rows.
That being said, you can place a table within a table in both versions which can provide the illusion of merged rows. Add a table to the report that and select a value to group on. Add the group on value to the first column in the grouping header. In the second column of the grouping header insert another table. Add to that table the values and details that correspond to the grouping value that you wanted to merge rows across.