Okay for future reference this could be one answer:

Check the Autoload and Kernel path by $Path.

One can then add the desired PATH (in this case /Users/gkdgoutam/Softwares/HEP_Softwares/MT ) inside

/Users/gkdgoutam/Library/Mathematica/Autoload/init.m

For example:

$MTPath = "/Users/gkdgoutam/Softwares/HEP_Softwares/MT"
If[Not[MemberQ[$Path,$MTPath]],$Path = Flatten[{$Path, $MTPath }]];

Then add the Autoload/init.m in Kernel (if not done already) i.e. in

/Users/gkdgoutam/Library/Mathematica/Kernel/init.m

by adding the following:

Get[ToFileName["/Users/gkdgoutam/Library/Mathematica/Autoload","init.m"]]

Okay for future reference this could be one answer:

Check the Autoload and Kernel path by $Path.

One can then add the desired PATH (in this case /Users/Softwares/HEP_Softwares/MT ) inside

/Users/Library/Mathematica/Autoload/init.m

For example:

$MTPath = "/Users/Softwares/HEP_Softwares/MT"
If[Not[MemberQ[$Path,$MTPath]],$Path = Flatten[{$Path, $MTPath }]];

Then add the Autoload/init.m in Kernel (if not done already) i.e. in

/Users/Library/Mathematica/Kernel/init.m

by adding the following:

Get[ToFileName["/Users/Library/Mathematica/Autoload","init.m"]]