d, Sql Server - rextester

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declare @country table (id int, country varchar(100))

insert into @country select 1, 'India'
insert into @country select 2, 'Australia'
insert into @country select 3, 'Canada'
insert into @country select 4, 'France'
insert into @country select 5, 'Russia'

declare @second table (id int , [user] varchar(100), country_id int)

insert into @second select 1, 'Ojas', 1
insert into @second select 2, 'Raj', 1
insert into @second select 3, 'John', 3
insert into @second select 4, 'Robin', 2
insert into @second select 5, 'Mary', 5
insert into @second select 6, 'Kamal', 4
insert into @second select 7, 'Bipin', 5
insert into @second select 8, 'Rohit', 1

SELECT c.id AS country_id, 
       c.country, 
       t.[user] 
FROM   (SELECT s.country_id, 
               s.[user], 
               Row_number() 
                 OVER ( 
                   partition BY s.country_id 
                   ORDER BY s.id) rn 
        FROM   @second s) t 
       LEFT JOIN @country c 
              ON t.country_id = c.id 
                 AND t.rn = 1

View schema
Execution time: 0,03 sec, rows selected: 8, rows affected: 13, absolute service time: 0,25 sec, absolute service time: 0,27 sec