Generally, the salary is computed as

Basic : 30 - 35% of CTC

HRA : 50% of Basic

DA : Regulated by Govt. notifications (nominal amounts)

CCA : Is normally a filler on negotiated salary (put the balance amount in

this). Otherwise, 30% of CTC

Gratuity : Is statutory (consider 4.81%)

Superannuation : 15% - 27% of basic (27% if there is no PF)

Leave Encashment : Taxable under provision of IT Act.

Tax deduction is based on various things like HRA claim (least of the 3 conditions under the IT Act - could also be non-taxable if claimed properly), investments done by employee, attraction of 80C/cca, (basic, cca fully taxed based on IT slabs), etc. Please refer to the IT Act (direct taxes) or your Finance deptt for more details..)

The above comp. structure can be tweaked or more components added based on the Co's requirements. That needs a discussion.....It may vary co. to co. or industry to industry