It is not Benami  transaction

2) money was given by father to son for purchase of property it would not be regarded as Benami property 

3) Property held in the name of the spouse or child are not Benami 

If money used for buying property is through undeclared sources of income it would be regarded as Benami property 

See 10 years prior there was no cash amount rule for buying property. 

Secondly income tax department now cannot assess these case it would be barred by limitation.

See before 2016 if the property was purchased in name of wife or children from known source of income then it is not benami. If the source of income cannot be explained then it is a benami transaction.

See the department can attach the properties retrospectively but it was purchased in name of wife and children which was not benami under earlier law. Property in name of child or spouse from know source was not benami property.

1. The cash given to son will be considered as gift to son

2. if that is so, the land bought using such cash, will not be considered as benami

3. even otherwise money given to children or property bought by a parent in name of child do not come under benami transaction as applicable before its amendment in 2006

4. the income tax dept cannot initiate any action now since it will be considered as time barred 

notices can be issued if the assessing officer has in his possession books of accounts or other documents or evidence which reveal that the income that has escaped assessment amounts to Rs 50 lakh or more in a year or in aggregate of four assessment years. 

The benami act in 2016 made it benami property, further the department cannot go beyond limitation. 

benami  transaction act 1988

 Exceptions were made for the purchase of property by any person in the name of his wife or unmarried daughter and it shall be presumed, unless the contrary is proved, that the said property had been purchased for the benefit of the wife of the unmarried daughter

2) benami transaction amendment act 2016 specifies certain cases will be exempt from the definition of a benami transaction. These include cases when a property is held by: (i) a member of a Hindu undivided family, and is being held for his or another family member’s benefit, and has been provided for or paid off from sources of income of that family; (ii) a person in a fiduciary capacity; (iii) a person in the name of his spouse or child, and the property has been paid for from the person’s income; and the Bill defines benamidar as the person in whose name the benami property is held or transferred, and a beneficial owner as the person for whose benefit the property is being held by the benamidar.

3 The Delhi high court has said that a property purchased by he husband  in the name of his wife from known sources can’t be treated  as benmai property. . in your case it is bought from unkown sources of income and would be regarded as benami property 

Benami essentially means property without a name. In this kind of transaction the person who pays for the property does not buys it under his/her own name. The person on whose name the property has been purchased is called the benamdar and the property so purchased is called the benami property. The person who finances the deal is the real owner.

If the property is held by the father for his child from known source of finds it will not be a benami property.  

Benami Transactions (Prohibition) Act, 1988 is an Act of the Parliament of India that prohibits certain types of financial transactions. The act defines a 'benami' transaction as any transaction in which property is transferred to one person for consideration paid by another person Such transactions were a feature of the Indian economy, usually relating to the purchase of property (real estate), and were thought to contribute to the Indian black money problem. The act bans all benami transactions and gives the government the right to recover property held benami without paying any compensation.

However from your contents there can be no benami transactions, even you say that he bought the property on hs son's name around 10 years ago, what is the proof for that now? 

His father can buy land on his son's name which cannot be considered as benami transaction.

The benami transaction if prohibited and this act came into force on 5 September 1988.  Therefore the property purchased 10 years ago cannot be considered as benami transaction, dont be confused by the term tax evasion.

If his father was a tax assessee and he has filed the ITRs of that year then if this money was paid by him it will come under illegal transaction but do you have proofs for that? 

You can consult a CA about it who will give you a clear picture about it, if you want to proceed legally then you may have to have proper evidence to prove your statement.

enami transaction (Prohibition) act,1988 came into into force on 5 September 1988. 

Therefore there can be no benami property bought, or do you have proof for the property bought by benami?

Until it s proved to to be  a benami property the income tax department cannot take any action