Your code compiles w/o errors which means that one of the fields you're referincing in the query doesn't exist in the tables.
There's no good reason to use RIGHT JOIN. You can use LEFT JOIN by swapping tables.Also, applying WHERE conditions to the table that may not have matching records effectively kills outer join. Such conditions should be moved into join conditions.

>what is mistake in this sql
>
>

>SELECT Student.*, Examtran.*;
> FROM ;
>     student ;
>    RIGHT JOIN examtran ;
>   ON  Student.code = Examtran.code,;
>  (Cast(Sum(obt01) As I)) /Count(code)  As CW,;
>	(Cast(Sum(obt02) As I)) /Count(code)  As HW,;
>	(Cast(Sum(obt03) As I)) /Count(code)  As Calli,;
>	(Cast(Sum(obt04) As I)) /Count(code)  As Clean,;
>	(Cast(Sum(obt05) As I)) /Count(code)  As Presence;
>	WHERE year=2006 AND bex=2.and.Student.admtd = 1;
>		GROUP By lcode,Sec,code;
>	order By lcode,sec