Pending Registration due to legal case which was unknown during registration

I was buing a house in karimnagar in 2017 July. I have verified initially with all the details from registration office and transferred the aggreed amount to the previous owner during registration and then we got to know that there was a legal case registered on the same house which is having hearing every 6 months from 2015 and the case could be prolonged for few more years (4 Lakhs money debts issue from previous seller to the buyer). Now the sub-registar confirmed that he can only do pending registration. I have spend all my life time savings and earnings on this property and i am completely depressed with this sudden shock. Please suggest on further steps The case which is running on this property is not in my hand to control because we dont have any contact details with the previous buyers/sellers. Can you also give me one clarity on what is pending registration and when can we get full rights on this property. We are facing issues in Mutation process now on this same property. Thanks, Srikanth