[Solved] SQL Server Error: Subquery returned more than 1 value

I am getting error when i try to run this code.

CREATE PROCEDURE [dbo].[UPdateDatereturn] @c nvarchar(50) AS 
BEGIN
    DECLARE @admno nvarchar(50)
    DECLARE @class nvarchar(50)
    DECLARE @types nvarchar(50)
    DECLARE @Rdate datetime
   exec Sendtempnexterm @c
    DECLARE @Sum INT = 0
    DECLARE @Counter INT, @TotalCount INT
    
    SET @Counter = 1  
    SET @TotalCount = (SELECT COUNT(*) FROM temp)   
    WHILE (@Counter <= @TotalCount)
    BEGIN
        SET @admno = (SELECT admno FROM (SELECT ROW_NUMBER() OVER( ORDER BY (SELECT 0)) RowId,* FROM temp) t WHERE t.RowId = @Counter)
        SET @types = (SELECT stdtype FROM (SELECT ROW_NUMBER() OVER( ORDER BY (SELECT 0)) RowId,* FROM temp) t WHERE t.RowId = @Counter)
       SET @Rdate = (select Dreturn FROM setdates2 where [class] like '%'+@c+'%' and studenttype=@types)
       
        IF @types='DAY' 
        BEGIN
           
                UPDATE P3P7 SET Returnsd =Convert (datetime,@Rdate,103)  WHERE admno = @admno
         
        END
       
	   ELSE IF @types='BOARDER'
        BEGIN
           
                    UPDATE P3P7 SET Returnsd = Convert (datetime,@Rdate,103) WHERE admno = @admno
           
        END
     
        SET @Counter = @Counter + 1
        CONTINUE;
    END
END

Msg 512, Level 16, State 1, Procedure UPdateDatereturn, Line 18
Subquery returned more than 1 value. This is not permitted when 
the subquery follows =, !=, <, <= , >, >= or when the subquery 
is used as an expression.