Company not honouring Notice period - can I question my company legally for cheating/misleading

I have a notice period of 3 months in my offer letter and there had been no changes to it either verbally or through email.Last week , I had put down my papers and now I am being told that tomorrow is my last working day. I have gone through different posts ( which were all answered on behalf of HRs perspective). Since line between HR policy and legal process is blurring, what I want to know is can I question my company legally for cheating / misleading. HR mentioned they can give 2 months of remuneration in case they terminate, which they cannot because I have already quit.
If 3 months is way too much notice-period, they should not have modified their company policies. When I resign they want to 'push' me off ASAP. Mind you, they do not have any basis on behavioural or technical front. By misleading information on notice period, they are putting me off-work for couple of months - a career blot, loss of money and mental agony. I am attaching excerpt from my offer letter. Let me know what options I have.

Whether the employee is a probationer or a confirmed employee, he has to fulfill the notice conditions of exit on his resignation. Either he may serve the entire notice period or pay the notice salary in lieu thereof depending upon the effective date of resignation. If the resignation is effective from a future date, he should be allowed to serve the entire notice period and if it is with immediate effect, he has to pay the equivalent amount. On the contrary, if the employer chooses to relieve him forthwith, he has to pay the notice salary for such an act amounts to a counter offer by the employer.

As the saying goes: "what's sauce for the goose is sauce for the gander"
On a plain reading of the extract of attachment ,the company should have given you 2 months pay/severance pay.
Put up a demand for two months pay based on offer letter-polite but firm words and wait for response.
After that send a legal notice and see the reaction.

It may not be an easy option to fight legally basing on this employment letter given the fact that you had resigned voluntarily and the employer does not want to wait for the notice period, had accepted it with immediate effect. You could have found out if it was required to give the notice of two months or not before putting in the papers. Also you need to have the relieving letter from the existing employer for any future usage. Though we can sympathize your situation, legally there may not be much you can do. The employer can always state they had wasted their time investing on your training etc which is difficult to wish away. It may lead to quite a few unsavoury issues which are best avoided as it might disturb you both physically and emotionally.

""Last week , I had put down my papers and now I am being told that tomorrow is my last working day.""
Company is violating its contract with employee.
""Last week , I had put down my papers""
What was the date of exit as given by you to the company-- After three months or immediate or ??