1. Though the owner has right to demolish the tenanted premises for the purpose of re-development, the same has not given unfettered rights to the landlords to so so at his will.
2. If you want to delay the demolition then you can seek legal intervention by way of civil suit for declaration and injunction . Though the landlord will get eventually the right to develop the same and give the fresh tenancy in the developed portion, the delay it would cause would give you much needed breather.
3. You can also negotiate with the new landlord to delay the development works.