Dissolve citric acid crystals in water and keep aside.
Bring the milk to a boil, reduce the flame.
Add citric acid solution to the boiled milk gradually to get soft paneer. Don't add everything together. You will see a greenish whey (if not, then more curdling is required. Add more citric acid solution)
You can use vinegar/lemon juice if you don't have citric acid crystals.
Once the milk is curdled, switch off the flame, add 1 cup of cold water in it and keep covered for 15 minutes.
Pour the curdled milk into a muslin cloth and tie it above the sink for about 15 minutes so that the whey gets drained easily. Gently squeeze the bag. Make sure that all the whey has drained.
Place the chenna (paneer) on a plain working surface and knead with the heal of the hand til the grains disappear and chenna becomes soft and creamy.
Divide the mixture into 8 balls.
In the pressure cooker add 1 cup of sugar and 3 cups of water and bring to a boil on high heat stirring in between till all the sugar is dissolved.
Carefully place chenna balls in the syrup one by one. Close the cooker and put whistle. Keep on medium flame till 1 whistle and then reduce heat to simmer and cook for about 7 minutes.
How to know if the Rasgullas are done? : Take plain water in a glass and dip the rasgulla in it. If it sinks to the bottom then it is done. If it floats then cook them for few more minutes.
Switch off the flame and allow the cooker to cool. You will see chenna balls doubled up in size.(use a wide size cooker). Remove balls from the sugar syrup.
Add remaining 1 cup of sugar in the syrup. Bring it to a boil. Let it cool for 10 minutes. Now add balls into the syrup. Keep for around 30 minutes.
Decorate with saffron strands.