Conveyance allowance exemption

you can take full of 2400..

As per section 10(14)If the travelling is between office and residence then conveyance allowance is not exempt from tax.because it will treated as perquisite U/s 17(2). Other than above mentioned journey, conveyance is exempted as per the following criteria

 Amount of allowance or amount totally utilised for the purpose whichever is less is exempt from tax.

the exemption in this case would be 2400 (800*3) ..since as per the rule max exemption is 800 per month

and urs is within the limit

The conveyance exemption is Rs. 800/- P.M , As per your Case the total amount is Rs. 2400/- for 3 Months so its within the limits of Rs. 800/- P.m . Therefore, you can take Rs. 2400/- as conveyance Exemption.

800*3=2400.

Transportation allowance is exempt upto 800 p.m for travelling between residence and office. In your case your income is exempted

exmpt upto 800/- p.m no doubt

Your system error is tolerate because it assess on end of the year so you can adjust with next month, in connection of Conveyance Allowance Exemption i think you are tolking trasportation allowance under other allowance section 17(2), if he are using employer source of trasportation than he can not use this exemption 

@ purav in your case conveyance allowance exemption is 2400. do not treat it as transport allowance.