Fixed asset entry in tally

Fixed Asset loses it value as they get old or wear and tear,etc.
Depreciation charges annually to effect this changes in value of Depreciable Fixed Asset.
During the sale or disposal of Fixed Asset you may write off the entire or remaining book value of the asset.

Disposal of Asset or Asset Write off A/c Dr.
To Fixed Asset A/c

Profit & Loss A/c Dr.
To Disposal of Asset or Asset Write off A/c  

Hope this helps