Admission to all top B- Schools is based on entrances like CAT/XAT/CMAT/GMAT... If you are able to score well in any of these tests you stand a good chance. Although some BSchools do give some weightage to class 10 and 12 results, a candidate with a 2 year work experience is at an advantage over a fresh graduate as work ex is given priority and weightage.
So if you can work hard and score very well in CAT or XAT ... you will e definitely able to get admission in one of the good B-Schools.