Write to the committee to call for a meeting for resolution of the problem. However, if this does not rectify the problem, you can approach the registrar of socieities for the same
Yes, you can challenge the gift deed and also file a suit for partition to claim your share in the property and if the Gift Deed affects your share in the ancestral property.
You can file a suit or writ petition against BDA from interfering with your possession of the property and to restrain them from taking over the possession of the property without following due process of law or in the alternative you can file a suit on the basis of your title before the civil court in Bangalore.
Adverse possession cannot be claim if the owner has permitted you to use the immovable property under any agreement and/or license etc. or if the owenr has taken steps against you for illegal occupation of the property within a period of 12 years from the date of your such occupation.