Use the following command to fix incorrect tag usage:

edit

i was trying to add my robotic arm to the rebuild world

xacro: in-order processing became default in ROS Melodic. You can drop the option.
Deprecated: xacro tag 'property' w/o 'xacro:' xml namespace prefix (will be forbidden in Noetic)
when processing file: /home/akash/project/src/techman_robot_ros-master/tm_grasp_description/urdf/tm70

0.urdf.xacro
included from: hrwros.xacro
Use the following command to fix incorrect tag usage:
find . -iname "*.xacro" | xargs sed -i 's#<\([/]\?\)\(if\|unless\|include\|arg\|property\|macro\|insert_block\)#<\1xacro:\2#g'

redefining global symbol: pi
when processing file: /home/akash/project/src/techman_robot_ros-master/tm_grasp_description/urdf/tm700.urdf.xacro
included from: hrwros.xacro