Nothing will happen, no role of advocate, Rebuff them straight, not interested. For any nuisance/threat, complain to police. 

Return the engagement ring and all other gifts received by you 

2) it should be mentioned in writing that there are no claims pending and that all articles , gift s have been been returned and you would not take any legal proceedings against your ex fiancee

1. Nobody can force an unwilling person to get married by use of force, threatening, etc. The decision to marry cannot be unilateral and has to be bilateral.

2.  Your decision of cancelling the marriage with him has to be informed to your parents and take their help in cancelling the marriage

3.  If forcefully you are dominated to agree for marriage, take the help of women groups, as well as local Police.

See give a complaint before the police station that you are breaking the marriage and exchanging the gifts given further see the guy side always wants to end this peacefully as women can file for any dowry demand complaint in such cases so there wont be much issue.

Both of you are adult and can take decision as per your choice this is nothing illegal to call after marriage in case you are not finding your fiance as compatible you can call up the marriage as you have already notified to them and let them take any decision there will be nothing happening you just stick to your decision and go ahead

Engagement is not recognized in any marriage law. 

Only marriages are not recognized.

You can choose to share the expenses incurred for engagement ceremony as a good will gesture.

There is no compulsion/ law that you are liable to repay the expenses for engagement ceremony or pay money as compensation for cancellation of wedding proposal.

Dear Madam,

You can tell him and his parents in legal language by issuing a legal notice and cancel the forthcoming marriage. It must contain some legal points also otherwise they raise some objections. 

You can say no to the wedding. If you are not comfortable. 

If you don't want to proceed further with marriage than you are free to live your life as per your wish.

According to Article 21 of the Constitution of India – Right to Life and Personal Liberty

Dear Querist

If you are not ready to accept this relationship, forget it and immediately announce the call off. no need solemnized this marriage.

Engage any lawyer from your side if they threaten to you or force to solemnized this marriage.

if possible return all the items provided by them and get your's too in writing.

Feel Free to Call

There is no problems involved in calling of marriage after divorce particularly of girl want to call if the marriage. 

Just exchange the rings back and marriage will be cancelled.

If you do not want to marry him and want to break this engagement, you may send a letter to them by registered post communicating your decision to cancel the marriage proposal for the reasons you rely upon.

You may agree to return their engagement ring and they in turn return your side ring.

If they threaten any other legal action then you also consult  a local lawyer and tackle the same legally as per law.

Dear Madam,

I cannot say anything about criminal legal consequences but one may have civil legal consequences. Generally engagement is treated as agreement to marry in future. If you never engaged, you need not worry. But if you engaged with someone to marry, you should know that you are in a binding contract.

According to section 65 of Indian Contract Act any person who has received any advantage under such agreement or contract is bound to restore it, or to make compensation for it to the person from whom he received it. So, if you got any valuable gifts, engagement ring, or money, you must return it to avoid a suit by the other party entitled to claim in the Court of law.

According to section 73 of ICA, “when a contract has been broken, the party who suffers by such breach is entitled to receive, from the party who has broken the contract, compensation for any loss or damage caused to him thereby, which naturally arose in the usual course of things from such breach, or which the parties knew, when they made the contract, to be likely to result from the breach of it.

Such compensation is not to be given for any remote and indirect loss or damage sustained by reason of the breach…”

If the other party made arrangements for booking a club or hall or bought required goods for the purpose of engagement or marriage or both, the other party may sue you to recover compensation for such loss or damage.