You should try to read the error log and search it on forum.
Your issue is nothing new.
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16:21:24.011 - info: NV_L4T_FILE_SYSTEM_AND_OS_T186_COMP@JETSON_TX2_TARGETS: 1. The root filesystem, provided with this package,
16:21:24.011 - info: NV_L4T_FILE_SYSTEM_AND_OS_T186_COMP@JETSON_TX2_TARGETS: has to be extracted to this directory:
16:21:24.011 - info: NV_L4T_FILE_SYSTEM_AND_OS_T186_COMP@JETSON_TX2_TARGETS: /media/ubuntu/OldUbuntu/TX2/TargeHW/JetPack_4.6.2_Linux_JETSON_TX2_TARGETS/Linux_for_Tegra/rootfs
16:21:24.011 - info: NV_L4T_FILE_SYSTEM_AND_OS_T186_COMP@JETSON_TX2_TARGETS: -----------------------------------------------------
Please make sure the disk you are using to download sdkmanager is ext4 partition.