You have toi format the numbers by leading zero
try this
--create a temporary table
create table #tmp
(
amonth int ,
ayear int ,
acombine varchar(8)
)
--insert dummy data
insert into #tmp values (1 ,2016 , '201601')
insert into #tmp values (2 , 2016 ,'201602')
insert into #tmp values (3 , 2016 , '201603')
insert into #tmp values (11 ,2016 , '201611')
insert into #tmp values (12 , 2016 , '201612')
--to get exact 'acombine' value try this
select CONVERT(NVARCHAR, ayear)+ Right('00' + Convert(varchar(10),amonth), 2) as acombine from #tmp
OP will be
201601
201602
201603
201611
201612
Thanks