Agreed with Ruchi.
Revaluation account can't be credited as this process is not revaluation but its recording at fairvalue. Moreover, as per AS-10, selective revaluation is not permissible, but we have ro revalue the entire class of assets. Therefore, you may need to revalue the entire class of computer and computer peripherals, if you opt for adjustments in revaluation reserve account. So, in my opinion, its better to credit general reserve account.
And, certainly, in any case, you cant depreciate the nominal value of printer, as there is no cost to be spread over the life of the asset.
Alternatively, you can also treat it as income and transfer it to p&l, as this is a non monetary benefit arising to the organization. In any case, this may be taxable u/s 28(iv). Therefore, if you can procure an invoice from the supplier showing separately, the value of the computer and printer as 45k and 5k respectively, it would be the best option.