ADDITIONAL SYSTEM INFORMATION :
Tested in Windows-10 and MacOS 12.1.
This bug seems to be appearing for all OSes(Windows/Linuix/Mac) for any Sanskrit-Derived-Languages like Hindi, Telugu, Kannada,etc

A DESCRIPTION OF THE PROBLEM :
JTextBox/JTextArea does not handle Hindi Characters properly in some cases. In correct case( as in Apple
 Notes, Safari URL text box), When using Devanagari-Keyboard(built in MacOS), if we wanted a character-combo like किम् one need to type following english-chars: 'kimf'

But if we use any Java-GUI that is built using java.swing or java.awt apckages *TextBox/etc, we get following chars (for the same sequence 'kimf'): किम ्

To get correct sequence, one needs to press backspace-key to get किम्


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Install & Devanagari-QWERTY keyboard in Mac
Run any Java-GUI which has testbox/textarea
Start typing chars: kimf , you should see किम् (for correct behaviour), for biggy case: you will see किम ्


ACTUAL -
किम ्

---------- BEGIN SOURCE ----------

import javax.swing.*;
public class Main {
    public static void main(String[] args) {
        JFrame f=new JFrame();//creating instance of JFrame
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JTextField b=new JTextField("click");
        b.setBounds(130,100,100, 40);

        f.add(b);

        f.setSize(400,500);
        f.setLayout(null);
        f.setVisible(true);

    }
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
To get correct sequence, one needs to press backspace-key to get किम्

FREQUENCY : always