How to apply for correction in partition deed done in 1979.

I have an ancestral agricultural land in Tamil nadu purchased by fore fathers in 1950 with a ground water well in it that is shared with a third party other than my fore fathers. And a partition deed is done in 1979 between brothers (My fore fathers). In original Deed - for purchase in 1950 - we have the rights on the ground water well in the land is clearly mentioned as half of it. And remaining half of the well sold to some other party other than both the brothers. In the partition deed (within brothers) done in 1979 - there is a mistake where they claim to have only 2 out of 7 parts/days rights in the the ground water well. Now the third party is using the entire well and for 7 days a week with pipes laid on our land - and not allowing us to put fencing for our land claiming they have the majority share in the well. And we are not staying in our native place any more to have any local influence. We only have a farm house which we visit intermittently. We enquired for correction deed in local sub registrar office - and they are claiming that this rectification deed will cost more (in lakhs) as the registration fee for correction deed will include the current value of the property and for the entire list of properties in correction deed. So suggesting us to negotiate with the third party in panchayat to give them a little compensation to close the issue. Not sure how to proceed with fencing our land. Please provide any inputs on this.