Claim for reimbursement due to road accident

Hello everyone, i am rahul mandal. my sister met an accident on 20 march 2017,and was severely injured on head.she was on ventilator for 12 days.she had diffused axonal injury on head and multiple fracture,in all it comes under grievous injury.and she is not mentally stable till now. About her- age 30 female education : masters in pharmacy occupation : head of department (quality check) in a pharmaceutical MNC. she was travelling by sleeper chartered bus to indore around 3 am which when reached ashtha(m.p) around 4:30 am,met an accident due to rash driving of the bus driver which clashed into an truck.the impact of accident was so hard that after breaking the glass she fell out of running bus and got multiple grievous injury all over her body which was also consider as threat to her life. now we are trying to go for reimbursement and compensation from either of the party(bus or truck or both).i have collected the charge sheet from the respective court where the case has been filed.after receiving the file of charge sheet i found that police put a statement of my sister which they never took as she was not in the condition of giving any statement and tried to turn the case in favor of big giant bus company.they also changed my statement as well and wrote the things which i never told.they tried to put the case in favor of bus company and against the truck.but the actual fault was of bus driver which i confirmed from the fellow passengers as well.the bus company also didn't informed us of accident and on calling again and again why our passenger didn't reach her destination on time they lie to us rather than telling us about the accident that the bus has some mechanical issues that's why its late and on middle of somewhere so may be that's why ur call may not be reaching your sister. now on investigating,we found that truck don't have any insurance.and as the case is turned toward truck party,and bus party is not on faulty side.whom should i ask for compensation and reimbursement.as our advocate is saying that it would be difficult for us now to get compensation as truck don't have any insurance. shall we claim the bus company in which she was travelling.i had her bus ticket,all the hospital bills and medicine bills it more than 8 lakhs and still it need 5-6 lakhs for her. important concern: 1. whom should i ask for compensation and reimbursement.(bus or truck or both) 2. How much compensation should i claim (keeping in mind her education,and future aspects). 3. what if truck party don't have vehicle insurance. 4. what if bus party refuse to compensate saying its not there fault as case is against truck. please reply with the best possibles thank you and regards.