Your rental income would be taxed under the head income from house property and you will get 30% standard deduction against that income and so you cant claim any other expense against such income other than house loan.
As far as business income is concerned you can claim expense of all expenses incurred for such business.
You can save tax by investing in LIC, PPF, ELSS mutual fund etc upto Rs. 1.5 lakh, or invest in medical policy, if your 1.5 lakh limit has been exhausted you can further invest in NSC upto more 50,000.
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