They can carry on additional construction after obtaining sanction from BBMP 

2) file RTI application to find out whether construction of additional floor has been sanctioned 

3) if construction is unauthorised additional floors can be demolished 

You have to file RTI with building proposal department of BBMP as to whether building plans have been sanctioned for 15th floor of your building 

2) you can also check RERA website as to whether building plans have been sanctioned for 15 thfloor 

If the building is built according to the Municipal
Corporation/ Committee by-laws and the plan has
been passed and there is no ongoing dispute on the
landed property or the building built there upon then
it is not illegal.
Since, permissions have been taken for all the 11
floors, the lower 11 floors are not illegal, it is
completely in accordence to the law.(assuming no
other problem)
But as said the 15 floor is built without taking
permissions fro the concerned authority or passing
of the plan, the very floor is illegal. Not the whole
building and additional floors can be demolished. 

Go to the RTI Online website.

For submitting RTI click on Submit Request, and you will be see the Guidelines for use of RTI online portal. Read the instructions. 

1. See there shall be order of approval from authority you need to check same along the certificate.

2. You can verify same with the municipal authority.

You can obtain same by filing RTI application.

3. See if the plans are not approved the construction shall be illegal no loan and can be demolished.

4. Ask for indemnity bond and order of approval from builder.

See you can file an RTI in from prescribed with the PIO of concerned office and fee of rs. 10 for same can be paid.

You need to inquire the same through rti. They will give you appropriate information in the same

1. Previous Sanctioned Plans can be duly amended by the registered Architect-on-Record of the Builder. This usual and not against the law.

2. You can go personally to the "Building Proposal" dept., and give them the File No., (check IOD or LP numbers) and ask for certified copies of the all the earlier and amended plans.  This can be done thru your private agent /architect.

3. RTI Application can be filed on a 10/- court fee stamp application and ask for certified copies of the all the earlier and amended plans, of the project.

4. You can also anonymous lodge complaint to the Municipal Commissioner or Town Planning Dept., IF you suspect some illegal activities. No harm will come to you.

Illegal construction. In no case , builder will apply for lesser floors, so already maximum floor sanctioned, above 11 are illegal and will stay in continuous threat of demolition. No OC CC will issue.

Do not verify anything, just ask them to provide sanctioned order and cross check from department.

Third party information will not provide under RTI.

1. They cannot construct extra floors without approvals. 

2. You should make application under RTI act to get details of approvals related to your building. 

3. Authorities may levy fines upon builder and give approvals or order demolision of extra floors and will not issue completion certificate to building incase of diversion from approved plan.

4. Application under RTI will help you to confirm about approvals 

Dear Sir,

You may get all the details from BBMP by filing application under RTI otherwise you may approach some staff members or brokers otherwise it is very difficult to get such details.

No it will not effect registration of approved flats.

Flats till 11th floor would be legal and not demolished 

partial OC can be issued by municipal corporation till 11th floor 

Only illegal construction will demolish or seize. But due to illegal floor, OC will decline to whole project.

1. The illegal floors will not impact the legally constructed floors and neither will it attract any penalty for registration purposes. However to the exception of the legal floors, the OC will not be granted to the illegal floors which will keep attracting higher Property Taxes and other statutory levies, as per calculations of the local Municipal Corp.

1. As per Supreme court , extra floors not allowed , and needs proper approval before starting construction of the building.

2.  LP Number is the final approval number given by the authority after inspecting all technical aspects and is safe for real estate development.  You can verify the LP number from BBMP office or website.

- You can also know it after filing RTI application as well.

3.  If the extra floors are not approved from the Authorities , then there is maximum possibility to demolish the same, or may imposed fines as well upon builder.

4. If the extra floors are illegal , then it will not impact others approved floors legally , and have right to get all the necessary documents for registration 

In BBMP website

 http://bbmp.sahaaya.in

You will get 

Building Plan Approval

Plan Sanction Condition;

you will get

Highrise Plan Sanction General Conditions,

Download here

BBMP/ADDL.DIR/JD NORTH/LP/0------/2015-16

This Plan Sanction is issued subject to the following conditions

The details of all the doubts you have raised will be available in the above circular.

You can write a letter to the authorities concerned under RTI act ad can seek the information whatever you desire to get.

If any floor is found to be under illegal construction then the authorities may issue notice and initiate steps to demolish the illegal structure or floor, however this may not impact the flat owner whose flats have been approved by the competent authorities.