ASR will fall ill when he hears of Kh's shaadi - I don't think he'll react all that much on her engagement thinking she will still b around, since he is not getting married to La anytime soon-so what will cm to him as a SHOCK is her pending shaadi.
He will be grievously ill, bed-ridden. Either Kh will get her 'wind-breezy-something's wrong-feeling' and call up RM to inquire whether every1's okay and find out from OP that 'barray sahib' is not well. OR Anjali/La will make the courtesy call of congratulating Kh and say that ASR is not well.
Either ways, Kh will find out he is not well ON HER WEDDING DAY. She will rush to go to ASR in her usual night clothes (i.e. plain clothes, open hair rather than her usual working clothes 'chamkeli kameez + braided hair'). OR she will be in her wedding dress and still rush to RM.
Once there (OP will open the door), she will go to ASR's room. Meanwhile either ASR in delirium says her name (I think that's when Anjali will know who her brother loves) OR gets the 'wind-breezy-feeling-she's-there' and get up-only to see Kh standing beside his bed. He will palm his hand on her face and she will tell him to take the medicine to get energy to tell her he does not want to see her again...
ASR wil fall ill when he hears of Kh's engagement &pending shaadi (he got a headache ven he cudn't talk to Kh b4 'Character Dheela' scene). Kh on her wedding day will hear of this & cm rushing in her usual night clothes (i.e. not dressed up and with open hair), go to his rm & he wil kno she's there!