CREATE TABLE [dbo].[people](
    [id] [int] NOT NULL,
    [motherId] [int] NULL,
    [fatherId] [int] NULL,
    [name] [varchar](30) NOT NULL,
    [age] [int] NOT NULL,
PRIMARY KEY CLUSTERED
(
    [id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO

ALTER TABLE [dbo].[people]  WITH CHECK ADD FOREIGN KEY([fatherId])
REFERENCES [dbo].[people] ([id])
GO

ALTER TABLE [dbo].[people]  WITH CHECK ADD FOREIGN KEY([motherId])
REFERENCES [dbo].[people] ([id])
GO

INSERT [dbo].[people] ([id], [motherId], [fatherId], [name], [age]) VALUES (1, NULL, NULL, N'Adam', 50)
GO
INSERT [dbo].[people] ([id], [motherId], [fatherId], [name], [age]) VALUES (2, NULL, NULL, N'Eve', 50)
GO
INSERT [dbo].[people] ([id], [motherId], [fatherId], [name], [age]) VALUES (3, 2, 1, N'Cain', 30)
GO
INSERT [dbo].[people] ([id], [motherId], [fatherId], [name], [age]) VALUES (4, 2, 1, N'Seth', 20)
GO
INSERT [dbo].[people] ([id], [motherId], [fatherId], [name], [age]) VALUES (5, NULL, NULL, N'Saman', 48)
GO
INSERT [dbo].[people] ([id], [motherId], [fatherId], [name], [age]) VALUES (6, NULL, NULL, N'Thulsi', 45)
GO
INSERT [dbo].[people] ([id], [motherId], [fatherId], [name], [age]) VALUES (7, 6, 5, N'Jehan', 23)
GO
INSERT [dbo].[people] ([id], [motherId], [fatherId], [name], [age]) VALUES (8, 6, 5, N'Nithin', 22)
GO
INSERT [dbo].[people] ([id], [motherId], [fatherId], [name], [age]) VALUES (9, 3, 8, N'Chuti Baba', 7)
GO
INSERT [dbo].[people] ([id], [motherId], [fatherId], [name], [age]) VALUES (10, 4, 7, N'Loku baba', 8)

SELECT DISTINCT pp.motherId,pp.fatherId, pp.id
FROM people AS pp
WHERE pp.motherId IS NOT NULL AND pp.fatherId IS NOT NULL

SELECT FR.motherId,FR.fatherId
from (SELECT motherId, fatherId, age
FROM people AS pp
WHERE pp.motherId IS NOT NULL AND pp.fatherId IS NOT NULL
Group By motherId, fatherId, age) AS FR