The LR (new) dag no. Is the corresponding to RS (OLD) DAG NO.
IF YOU CAN'T FIND IT ONLINE, THEN YOU CAN HIRE ANY LAWYER TO SEARCH REQUIRED HISTORY REPORT OF THE PROPERTY ON BEHALF OF YOU, OR YOU CAN TAKE HELP FROM THE OFFICE CLERK/OFFICER OF THE REGISTRATION OFFICE/BLRO OFFICE, WHO CAN HELP YOU GET THE SEARCH REPORT, REQUIRED DOCUMENTS,ETC. ELSE YOU CAN YOURSELF VISIT THE REQUIRED BLRO OFFICE AND REQUEST THEM FOR GETTING THE REQUIRED PLOT INFORMATION AND CERTIFIED PORCHA AND OTHER DOCUMENTS ON PAYMENT OF THE NOMINAL FEES REQUIRED FOR GETTING SUCH COPIES.
AS PER YOUR POST, PREVIOUSLY THERE WERE 4 JOINT OWNERS OF THE PROPERTY. Now Both parents have deceased, therefore, of they have died intestate then the properties owned by them will be equally divided among the legal heirs of them. Until and unless, your mother had herself transferred by way of gift, will or sale, etc., your brother can't legally transfer it. But, if your brother says he has already got the mother side's ownership transferred to his name, then tell him to provide those documents which proves tgat your mother had given him permission to do so. If he had Done it after death of your mother, then if your mother had died intestate then you to have a share in her property. Mere name transfer cannot take away your rights.
If mutually or by way of alternative dispute resolution the problem is not solved then you can seek help from court. You can hire a good lawyer near your area for getting help in this regard.