I think I could guess the purpose of the employer. As we know, the CTC is what the employer spends for the employees apart from salary which is booked as expenses in the books of a/cs of the firm and accordingly IT computations takes place. It's seen in many employer that they aimed at showing the lowly paid employees as how much they really costs to the firm and wished to show all put together > Rs.10000 and it's not only Rs.4500.
Re.Fringe benefits, subject to the exemptions, whether shown included in the salary or stated separately under diff. heads these exp. gets added but still the FBT is payable, if applicable (as it is abolished in 2009 in the hands of employer)
Pl.read -01.12.2009
"The Indian government abolished the Fringe Benefit Tax (FBT) as part of its 2009-10 budget on 6 July 2009. This amendment, which shifts the burden of taxation on fringe benefits from employers to employees, will come into effect on 1 April 2010.
Fringe Benefit Tax was introduced in the 2005-06 fiscal year as a tax paid by employers on the portion of employee benefits not included within an employee’s salary. This included entertainment, gifts, concessional tickets for private journeys, employee stock options, etc.
As a result of the amendment, however, fringe benefits will now be taxed as perquisites and treated as taxable income. Employees will also be taxed on any sweat equity shares they own (shares given to employees on favourable terms), or employee stock ownership plans they participate in. They will also be taxed on any contribution in excess of INR 100,000 (USD 2,075) to an approved pension fund made by plan sponsors on their behalf."
In some firms the employer pays some Taxes incl. IT & FBT for and on behalf of the employees also.