There was no real investigation done and the document says there is enough proof to arrest all of them. can we question that proof? Do you think they were under high influence? I dont think there was any investigation done, they were just sucking in everything what my wife said.
A complaint in writing and your non-cooperation with the police shall be enough for the police to conclude about the prima facie evidence to the offence and can register a FIR and remand all the accused.
Hence it is advisable that your parents first try to obtain Anticipatory bail from court and then attend the inquiry session before police. Until then let them be in hiding to avoid police excess who may acting at the behest of your wife's considerations passed to them.
All other details what you have discussed shall be taken up during trial only and not before the police who will conduct preliminary inquiry into the alleged incidents.
My sister and my brother live abroad, do police have right to arrest someone outside India without any solid proof? without us questioning the proof?
Right to arrest is different from how to arrest the people who are residing in a foreign country.
If police are satisfied about the complaint and its genuineness, they can initiate legal action against the accused, you can challenge all those false allegations only in the trial proceedings and not before police.
The police will be determined to not to listen to your grievances nor they will be bothered to know about the actual facts.
This is police arrogance.
Your sister and brother need not visit India for this purpose. Let the police keep searching them. Finally the police will split the case and may conduct trial for you people separately and for them separately.
Afterwards you can apply for quash of case against them.
3. What should be my next step to negotiate with their family?
If they are ready to settle the matter by talks, you may offer them your rates as well.