how many ways get FIR number

You can search in the website of the concerned police station/District Police website and also can file RTI Application direct to State Public Information Officer (RTI) of that Police station and can obtain a certified copy of FIR.  Search in google.

you shoud find out CCTNS link of your state police then you will find a link for VIEW FIR on this web page

as example for UP-

https://www.uppolice.gov.in/article/en/cctns

Simplest way to do is approach the police station and ask them the details. If they are not giving you any details then you can ask by filing a RTI. Did they arrest you for investigation? How is it that you were not informed ?

Alternately, if FIR is registered then you can find out from the concern magistrate court.

FIR filed with Delhi Police can be viewed online through the website of Delhi Police. When you reached the portal of Delhi police to view copy of FIR three options will appear under the head FIR registered i.e. from 1.7.2015, before 1.7.2015 and M. V. Theft cases (Motor Vehicle Theft cases). If you Hit on any of the menu Delhi Police FIR Search Portal will open. The mandatory fields in the portal are District, Police Station, Year of FIR and FIR No. But you can search the FIR without FIR number also as explained below. Other information FIR date range is not mandatory. You can search the FIR on the online portal of Delhi Police by giving these basic information.

The steps to view First Information Report filed by Delhi Police on the website and process of entering information are explained below.

Steps to Search / View FIR online - Delhi Police Portal

 Step 1 : Visit the website of Delhi Police View FIR Link by clicking on the link

Step 2 : Chose the option under FIR Registered. From 1.7.2015, Before 1.7.2015, M. V. Theft Cases.

Step 3: Now FIR Search Option of Delhi Police online Portal is opened. The fields will appear in Horizontal format. It is shown here in vertical formation for convenience.

Step 4: Fill information in the field. District, Police Station, Year and FIR NO are Mandatory.

District - Enter District in which FIR Lodged

Police Station - Enter Police Station in which FIR lodged.

Year - Year in which you have registered FIR. Chose the year from drop down menu.

FIR No - Enter FIR number if you know that

FIR Date Range - Chose the date Range of First Information Report was registered (This is not mandatory)

Step 6: Hit Search Button.

Now FIR details will be displayed on the screen.

If you want to clear the information and enter new data, Hit on clear button.