I have a property with power of attorney

Hello,

If you have purchased property by executing power of attorney then it is perfectly in your name. Now you have to note the transaction in revenue records. In this case no need to have another registration in your name again as already you have registered document of your property. 

What do you mean by "I purchased a new property in delhi with power of attorney"?
A mere power of attorney holder is just an agent, not the owner.

If you have purchased the property, from a POA holder of that property without registration, contact a local advocate and take his assistance in possibility of  getting some deed by gifting it to your mother, and registering such gift deed in her name.   The gift can be styled in such a way that she has rights on the property during her life time, and after her, the rights come back to donor.

Get mutation first  of your house property in municipal records. Mutation is the recording of a transfer of title of a property from one person to another in the revenue records. The documentation procedure to be followed and the fee payable vary from State to State. 

There cannot be transfer of title except through a registered conveyance. The posting is incomplete in this context.

Which part of Delhi the property is located ? 

Whether the particular Khasra falls in the area where registration of Sale Deed is allowed?

Have to taken possession of the property purchased by you? If you are in occupation of the subject plot you may construct and start living therein.