Title of extra land and construction there on

What is the agreement conditions in this regard?

Your post is devoid of details hence any opinion rendered based on incomplete or vague information would be misguidance 

As per TNCP Approval area of plot is 152.64 sq m but there is extra land 0.5'*70 is available. Actual dimension of area available at site is 24*70. Builder is not mentioning actual dimension of plot in agreement. 

kindly let me know what details required as i am dont know about legal aspects.

This situation raises important legal concerns about the ownership of the extra land and your ability to obtain construction permissions. It’s crucial to seek legal advice immediately to ensure you're not missing any hidden issues in the agreement. I strongly recommend reaching out to me for a free consultation, so we can address these concerns and protect your interests.

The posting is short of material facts. Limited facts suggests that the property referred is an apartment and issue is related to proportionate are of land in common enjoyment. Unless the material facts are disclosed, it is impossible that there could be any meaningful suggestion.