I invested 50 lakhs with a 48% monthly return. How do I save the interest from income tax?

I am a retired govt. servant and get pension. Also I get Interest from Deposits, Saving and Acc. Int. I show this income in my Income Tax returns filed in Form ITR-1 SAHAJ. During the current Financial Year I have received the maturity amount of my PPF maintained in the Post Office. Out of the amount received I have a certain amount given as a gift to my spouse. She has invested the said amount received by her from me as a gift in the SCSS A/C and gets interest on that amount. I want to know whether the amount she receives as interest from the amount given by me is to be included in my income and to be shown in the Income Tax Return. If so, at what place i.e. in which column? I have to show the income so included as I do not see such places or column. In which I have to indicate this amount Sr. No. B3 Income from Other Sources along with the Interest received by me from Deposit etc. Since the amount of interest received by my spouse is included in my Income, Whether the said amount is also to be shown in her Income Tax Return or otherwise? As if it is to be shown in her return also then there will be duplication. This clarification is sought as I file my return myself and since the notice I or my wife may not get. I hope you will kindly guide me in this regard and oblige us. Thank you in advance.

Every month i transfer 30k to my friend account and my friend return it after 15 day. My salary is taxable.my question do i need the pay the tax on this amount which is 3.6 lac

Sir, I had invested Rs. 14 lac on name of my wife in PM vay vandna yojna. Whether I will have to show interest income in my return? Form no. 26AS of my wife will show above income. How to indicate in my wife's return that said income is already shown in husband's return?

Sir, I have around 30 lacs in FD, 15 lacs in SCSS and 4.5 lacs in post office MIS. What should I do to reduce my income tax on the interest earned.