Tax planning : house property taxation

As per my view, such rent agreement between you and your spouse seems vague.

Note : The appropriate word is 'tax planning' and not 'tax evading'.

but my all agreements i.e. purchase agreements, loan agreements all shows clear cut line of demarcation between me & my spouse that each one owns 50% portion. & further loan repayments also made accordingly 50% by me & 50% by spouse.

In this no vagueness  but still is there any chance that my tax planning will get in trap of tax evasion scheme any way or is anybody do such kind of plans or any case laws is there on such case.

If you are saying that the interest portion on your home loan comes to 10 lacs each, or 20 lacs combined in a financial year, you must have taken a very large home loan. A bank can give such a loan only on the basis of the borrowers repayment capacity - in 30% tax bracket. Secondly, it is clear that the house that you have purchased must be pretty big. You can live in a rented house, and give your purchased home on rent. The rent you receive can easily pay for the rent that you are going to pay. The interest deduction u/s 24(b) allowed shall be interest actually paid. 

Please recheck whether this amount you are saying of 20 lacs, is interest portion or EMI for the year.