Hi Kamal,
1. You should run TBB1 for original and netting contract on maturity date i.e. 30.06.2013.
2. TPM18 should also be run for both contracts on 30.06.2013. Following point 1 and 2 will off-set the effect.
3. You will have to run TPM1 for the original and offsetting contract until maturity since technically they are standing contracts.
4. The Profit/Loss will have to be posted for Contract 105.
Please let me know in case of further queries.
Regards,
Rohit