Please clarify the following according to Qur'an and Sunnah: -A) As I have given the Zakah on one complete year of possession of Rs.100, 000/- and if it increases by 25 percentages next year on which amount Zakah is obligatory? 125 or 25 percentages?B) What is the ruling of Zakah on closed and kept house not in use? Do we still have to pay Zakah on this house?2) What is the Takbeer we have to say on the festival days, including both festivals and how long we have to continue?

Praise be to Allah, the Lord of the World; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

You have to pay the Zakah due on all your money and its revenues every year, i.e. it is not sufficient to give only the Zakah for one year in the last few years as some people do. Then, you have to pay the Zakah on the total amount you have at the end of your Hawl (one lunar year), i.e. the revenues are to be included, since they become part of the total sum you have.
As for Zakah on a house, the house is not subject to Zakah, whether it is occupied or not, unless it is meant for the sake of trade. Then, if such a house is meant for trade, then it is obligatory to pay its Zakah every lunar year. Thus, it should be evaluated every year and if its value equals a Nisaab (the value of 85 grams of gold) by itself or by combining it with other money or articles of merchandise, then you have to pay 2.5 percentages as Zakah of the total amount of wealth.
As to Takbir during the days and night of the two Eids (al-Fitr and al-Adha), there are many forms. Here is one of these forms:
"Allah-u-Akbar (3 times), La Ilaha Illa Allah, Allah-u-Akbar (twice), Wa Lillahil Hamd". Such a form means: "Allah is The Greatest of all (3 times), there is no god but Allah, Allah is The Greatest of all (twice) and thanks are due to Allah".
The Takbir starts after the sunset of the last day of Ramadan and ends with the prayer of Eid al-Fitr.
As for Eid al-Adha, it starts from the dawn of the 9th day of Zul-Hijjah and ends at the 'Asr prayer of 13th day of Zul-Hijjah.
The above-named Takbir is the restricted form as explained. As for the free Takbir, it is in the first ten days of Zul-Hijjah.
Allah Says (interpretation of meaning): {And remember Allâh during the appointed Days. …} [2:203].
Allah knows best.