In such cases there must be an allegation that the accused had instigated the deceased to commit suicide, or secondly, had engaged with some other person in a conspiracy, and lastly, that the accused had in any way aided in any act or illegal omission to bring about the suicide,” 

2) “The intention of the accused to aid or to instigate or to abet the deceased to commit suicide is a must for this particular offence under Section 306.”

3) 

Without specific material or evidence, it'll be hazardous to ask accused to face trial

Hello,

Sorry to hear that but time is essence in criminal matter and any proceeding now will avail no result as all the prove and witnesses shall not support the case now die to a gap of two decades. 

Regards 

1) If you're not satisfied with the previous decision took by our judicial system. You can reopen case and ask for justice in high court.

You can initiate the legal proceedings can file a FIR but you need to explain the delay in FIR and you need evidence that your father and relatives abetted suicide of mother.

Abetment of suicide is most difficult task to prove.

Committing of suicide does not necessarily mean abetment was the reason behind this.

Though there is no time limit for opening of a criminal case of this gravity, after so many years your case of this nature would be almost impossible to get registered as FIR  or proved in trial.

Concentrate on your present profession or activities.

Good luck. 

 you can get the case reopened subject as mentioned under section 468 Cr.P.C to 471 Cr.P.C as the facts narrated above. In my opinion you can get the case reopened. First get the copies of all the documents.  Since the incident was 20 year old the chances of getting all the documents are bleak. Moreover in RTI Act you cannot get the documents / information more than 20 year old. 

1. You can file the said criminal case now if you have irrefutable evidence in support of your said allegation levelled against your father.

2. You have remote chance of getting favourable result since there will be hardl;y any evidence left to prove your father guilty.

Dear Sir,

There is no limitation for an offence punishable more than 3 years as per Sec. 468 of Cr.P.C.  Criminal law can be set into motion at any point of time by any person.  You can file a Criminal Petition U/s 482 of Cr.P.C. and get reopen that case.

No, it is not possible now at this stage.

It is not only barred by limitation but also not a strong reason to blame anyone on this.

It will be hit by limitation. You can file but you will have to convince the court for delay in the same