How to calculate 1st rank student with his total gross marks , the subject and marks which has maximum score

Do it in stages: first get the students total score and highest personal score, and get the highest scorer:

SELECT TOP 1 SNAME, SUM(Marks) As Total, MAX(Marks) As Highest
FROM MyTable
GROUP BY SName
ORDER By Total DESC

That returns one student:

SName  Total   Highest
SURESH	 291        98

Then JOIN that with the original table to get the subject as well:

SELECT s.SName, s.Total, a.Subject, s.Highest
FROM MyTable a
JOIN (SELECT TOP 1 SNAME, SUM(Marks) As Total, MAX(Marks) As Highest
        FROM MyTable
        GROUP BY SName
        ORDER By Total DESC) s 
ON s.SName = a.SName AND s.Highest = a.Marks

Result: one row, the info you need.

SName     Total   Subject  Highest
SURESH	    291   English       98

But...that is a very poor database design. You are storing the same info repeatedly, and should be using three tables: one for students, one for subjects, and one for results which uses foreign keys back to the others.