Company asking me to pay over and above of notice period days

Please note that I have recently joined one of organization in Hyderabad and I'm serving a probation period of 6 months, as per the Employment agreement one month notice period during the probation. it has been two months now I got a better opportunity in all aspects and I have put a notice period of one month, now company asking me to serve one month notice and pay over and above of 3 month gross salary. Since they have mentioned that in an employment agreement that u have to serve a minimum of one in the company else u have to serve notice and over and above of 3-month gross salary Further to above, it was an understanding that during the signing white paper that this clause is applicable only after the probation period and if any special training is provided by the company for the betterment of my personal skils. In My Case there is no Special training was given by the company neither my probation period is completed. Still my Company asking me to pay the money of over and above of 3 months gross salary which is way high Please help me in legal way to tackl this as they were not ready to pay my notice period salary saying that we will deduct in over and above of 3 months