If the result:
cname Cid
---------- -----------
sunil2 1 |
sunil7 3 |--- Values after deleting Cid values 2,4,6
sunil9 5 |
sunil11 7 |
sunil20 10 |
sunil60 13 | --- Cid values after altering the
sunil70 16 | identity increment using
sunil80 19 | Management Console
sunil90 22 |
sunil100 25 |
sunil110 28 |
If this is what you want the only way to alter the identity increment is to use the management console. Open the table in design view and alter the identity increment, close and save the revised table.
To the best of my knowledge there is no way to use T-SQL commands to accomplish the results as shown.