please could someone say how do I register to Mamta's kitchen.Many thanks for all replies.

Rosy, you do need to register to get into mamtaskitchen. That is only for the administrators.

How long should kamalkakari be boiled in the pressure cooker? I kept it for 20 minutes after the whistle and it's still hard.

They should have cooked in that time. They are probably not fresh or too old/mature/hard. Give them 20 minutes more and see what happens. You may want to add just a pinch of soda-bicarb (cooking soda) to the water.