Pooja, your queries suggest that you are ready to become an advocate, at least in your own case as they reflect an understanding of the process. Here are my answers and hope that you will represent yourself ASAP.
a) During my cross examination, if the opposite party asks me some question and I realize that I have some good evidence which can be produced for that question.....but it is not filed by me in court. Then can i produce it later on the next date ?
Good evidence should be filed at the earliest. There is no need to wait until a question is asked. Just file an application seeking to supplement or amend your affidavit. If you file it before the cross-ends, it will be easier for the Judge to accept it as it gives opportunity to the opposing party to cross-examine you on it. Even after your cross is over, you can file it providing some justification for not filing it earlier.
b) There could be some relevant evidence on cell phone instrument sometimes. Can that be shown in court during cross-examination. I mean if its has not been submitted for some reason or another, but it is available. Then will the judge entertain it ?
Again, you should reference such electronic data in your affidavit and quote the exact email/SMS in your affidavit mentioning that you will bring the evidence during your cross-examination and that if the Court or opposing party needs to verify it, you would gladly do so. If the authenticity is questioned and the evidence is very compelling, you should file an application to summon relevant officers of the ISP or Mobile carrier officers with a Court Order compelling them to verify the authenticity of the specific e-evidence.
c) Suppose I submit evidence. After that in-laws or hubby do something that can go against them and make my case stronger instead. How do I keep the judge informed of this new development ?
New evidence can be based upon new facts or newly discovered evidence. The procedure to be followed to bring it before the Court and get it recorded as an exhibit is based upon the status of your case. If your cross is not over, file an application to supplement your affidavit and get the new evidence in. If your cross is over but the other party's cross is not over, present the evidence during his cross. If all cross-examinations are over, file an application to "recall the witness" or summon the witness in which you present the new evidence and then have the opposing party or the party/witness to whom the evidence applies on the stand and present the new evidence. Recall is merely summoning a witness already cross-examined.
Finally... and this is VERY IMPORTANT: Make sure that all documents, electronic evidence or any material used as evidence is EXHIBITED by getting it marked a specific Exhibit number. You should then reference the exhibit number in your final arguments. This is something that 90% of advocates do not bother to do or confirm that it is done or know that this should be done. I suffered from this in my initial stages of litigation after which I decided to represent myself. How do you know that your evidence has been assigned an Exhibit number? Simple. Apply to get the Roznama or docket of the case and each exhibit will be described there. What do you do if you find one of your evidence document not marked as an Exhibit? File an application asking the Court to do so. However, you should be very attentive during all cross-examinations and make sure that your evidence is marked as an Exhibit with a specific number whenever it is presented. Be assured that Courts will not mark every evidence as an Exhibit simply because you have presented it. Absent an exhibit number, its evidentiary value is virtually zero and advocates in trial courts are blissfully unaware of this. WHen you go to High Court, smart advocates will tear your evidence apart asking the judge to not consider it because it has not been marked as as exhibit. They will say that it was not marked because you knew that it was fake or concocted or forged or whatever...
I am glad that you asked this question because it had caused a lot of stress to me during my litigation and I wondered how many others suffered from the same problem caused by inattentive or incompetent advocates. HOPEFULLY THIS RESPONSE IS ALSO USEFUL TO THOSE WHO REPRESENT THEMSELVES OR TAKE A CLOSE INTEREST IN THEIR LITIGATION, WHICH THEY SHOULD ALWAYS DO.