Inner Join Returns Multiple Duplicated Rows

Here is my query which returns multiple rows

SELECT
R.name, R.age,R.DOB,
ISNULL(D.Doc1,'NA') AS doc1,
ISNULL(C.Doc2,'NA') AS doc2
FROM
REQ R
inner join RES S ON R.Request_Id=S.Request_Id
inner join RES1 D ON D.Response_Id=S.Response_Id
inner join REQ1 C ON C.Request_Id=R.Request_Id

select * from RES1 where Response_Id = 111 -- return 3
select * from REQ1 where Request_Id = 222 --- returns 2

So at last inner join retuns 3*2 = 6 records , which is wrong here and i want to show 3 records in doc1 row and 2 records in doc 2 rows ...