Then send an intimation to the police through a registered AD regarding her threats to commit suicide and your apprehension that you may be implicated for it. This would create a veil of limited protection for you if she does end her life.

If your girl friend committed suicide and left a note against you then you can be arrested under section 306 of ipc for abetting to commit suicide. In case if you had physical relationship with her , you can be charged for rape on her complaint and for breach of promise of marriage.if she does not leave any note but her family and friends in their statement give your name as the cause of your gf suicide then also you will be in trouble .

Even if she commits suicide without taking your name & some body informs police that you are responsible for her death, then also you will face serious problem,

What you can do

Register a police complaint regarding threatening for suicide, as suicide is a criminal offence police will take action.

File a police complaint against the girlfriend and inform local inspector local police station that this girl is having suicidal tendencies and her threat against you also informed that you should not be held responsible in case such a thing happens. Inform the same to her parents and also to make her to attend counseling.

Suggestion

1. You should never have made any promise of marriage.

2. If you do not want to marry her then you should not have continued this relationship. Before putting a person in such emotional turmoil you should have kept the uncertainly of marriage shared with her

If she commits suicide and a prosecution is launched against you then you can argue that you had intimated the police regarding this earlier but it cannot overthrow evidence collected against you,

1) you can break off your relationship if your girl friend was having sex with another man

2) it was consensual relationship and you never promised her marriage .

3) in case girl friend files false case of rape obtain AB from sessions court

1. Audio/video record her such threats given to you,

2. Lodge police complaint against her for her giving you the said treat,

3. If you have decided to terminate the relationship with her, do not establish contact with her any further.

1. If she really takes any drastic step leaving a note that you are responsible for her taking the said step, your earlier police complaint against her threat, will be a good evidence to prove your innocence,

2. You shall have to preserve your audio/recordings carefully to place before the Court, if required.

Now she is saying she will commit suicide.

I didn't know she had a psychotic nature like this.

Her friends don't like me.

I don't know why.

I don't want to be arrested.

Please help.

If you find a persisting suicidal threat from her, you may better write a letter to her stating that it would unfair on her part to give such threats to you especially during the period where she is having relationship with another guy too, hence not to behave this way anymore in future or if you still go ahead with your suicidal plans, then I shall not e held responsible for your cowardly act.

Keep a copy of this typewritten letter with you and simultaneously file a NCR with the local police about this by enclosing a copy of this letter to her to be on the safe side.

What do you mean by veil of limited protection?

Without evidence of having intimated her about her such foolish acts there is no protection for you, so only the evidences will speak before law, secure them whatever it may be.

you should file a case under section 504/506 IPC if she gives threat about to commit suicide. and file an application for seeking protection order from the high court that no coercive action should be taken against you. then you will be protected from filing of any false case and issuance of any warrant or summon.