complain for missing luggage

my daughter NIKHITA SALUJA AGE 13 YEARS (MINOR)lost her luggage while travellin from Delhi to Patna in indian airlines Flight no.-IC 407 on 14/05/2009 PNR NO.- HXRURH..we hav not got any details regarding the lost baggage till now.The cost of whole luggage was approximately Rs.18000/- .
Kindly look forward towards my problem.