Purchase of immovable property

If your wife has sufficient income then you can file your wife return
If there is no such income and if you have income and filed the return then you can state the department same and as per clubbing provisions you can say that such income is yours but purchased asset on your wife name and such asset is not earning any income hence you had not shown any income of that asset in your return
Property can be appeared in the balance sheet of your wife as accounting is different from Taxation

Coming to the tax implication point.... The person who received the amount in cash might face consequences. Cash Receipt is not allowed as per section 269ST if the transaction value is more than 2,00,000 and in this case as your paying the amount, so there might not be any tax implications in regard to that

I think you can debit the capital account which will impact like you had gifted the amount to your wife and she purchased the asset(recommended). Or you can show it like you gave loan to her and she bought the asset with that amount but the problem is that in this case section 269SS will apply and you can't give loan in cash so penalty might arise(it might not arise as it comes under clubbing provision).