A catheter for mapping and ablating renal nerves distributed on the renal artery, comprising: a. a first set of electrodes comprising one or more electrodes configured to deliver one or both of electrical stimulation and ablation energy; b. a second set of electrodes comprising one or more electrodes configured to deliver one or both of electrical stimulation and ablation energy; wherein said first and second sets of electrodes (2411, 2421) are located at a distal end of said catheter, said first set of electrodes is nearer to the distal end of said catheter in comparison to said second set of electrodes; wherein the distal end of said catheter comprises a tubular structure (2204; 2304) that houses one or more resilient members (2200; 2300) with pre-formed curvatures, wherein said first or second set of electrodes is disposed on said one or more resilient members (2200; 2300), said one or more resilient members (2200; 2300) are attached at their proximal ends to a controlling shaft (2203; 2303), wherein movement of said controlling shaft causes said one or more resilient members (2200; 2300) to be pushed out of said tubular structure (2204; 2304) to resume the pre-formed curvature or retracted into said tubular structure (2204; 2304); characterized in that the catheter further comprises: - a controlling ring that sheaths said one or more resilient members, wherein movement of said controlling ring along said resilient members controls the extent said one or more resilient members resumes its pre-formed curvature, said ring controlling an amount of expansion of the resilient members when the resilient members and electrodes are pushed out of the tubular structure (2204; 2304) by the controlling shaft (2203; 2303); or - a controlling rod within said controlling shaft, wherein the distal end of said controlling rod is attached to the distal ends of said one or more resilient members, wherein retracting said controlling rod after said one or more resilient members are pushed out of said tubular structure will cause said one or more resilient members to bulge out at their middle. a. a first set of electrodes comprising one or more electrodes configured to deliver one or both of electrical stimulation and ablation energy; b. a second set of electrodes comprising one or more electrodes configured to deliver one or both of electrical stimulation and ablation energy; wherein said first and second sets of electrodes (2411, 2421) are located at a distal end of said catheter, said first set of electrodes is nearer to the distal end of said catheter in comparison to said second set of electrodes; wherein the distal end of said catheter comprises a tubular structure (2204; 2304) that houses one or more resilient members (2200; 2300) with pre-formed curvatures, wherein said first or second set of electrodes is disposed on said one or more resilient members (2200; 2300), said one or more resilient members (2200; 2300) are attached at their proximal ends to a controlling shaft (2203; 2303), wherein movement of said controlling shaft causes said one or more resilient members (2200; 2300) to be pushed out of said tubular structure (2204; 2304) to resume the pre-formed curvature or retracted into said tubular structure (2204; 2304); characterized in that the catheter further comprises: - a controlling ring that sheaths said one or more resilient members, wherein movement of said controlling ring along said resilient members controls the extent said one or more resilient members resumes its pre-formed curvature, said ring controlling an amount of expansion of the resilient members when the resilient members and electrodes are pushed out of the tubular structure (2204; 2304) by the controlling shaft (2203; 2303); or - a controlling rod within said controlling shaft, wherein the distal end of said controlling rod is attached to the distal ends of said one or more resilient members, wherein retracting said controlling rod after said one or more resilient members are pushed out of said tubular structure will cause said one or more resilient members to bulge out at their middle. - a controlling ring that sheaths said one or more resilient members, wherein movement of said controlling ring along said resilient members controls the extent said one or more resilient members resumes its pre-formed curvature, said ring controlling an amount of expansion of the resilient members when the resilient members and electrodes are pushed out of the tubular structure (2204; 2304) by the controlling shaft (2203; 2303); or - a controlling rod within said controlling shaft, wherein the distal end of said controlling rod is attached to the distal ends of said one or more resilient members, wherein retracting said controlling rod after said one or more resilient members are pushed out of said tubular structure will cause said one or more resilient members to bulge out at their middle.