How to change flashing address in Teensy 3.6

I am using the teensy 3.6 board.
I want to flash my firmware through boot-loader codes so I flashed boot-loader code using MCUExpresso IDE, and want to flash my firmware at address 0x0000C000, but my firmware is written in Arduino IDE and I want to change the flashing address to 0x0000C000. How can I change the flashing address in Arduino IDE for my firmware?

You should ask the PJRC.com forum group for questions of this nature. PJRC Is the Teensy series developer.

Thanks for your reply, but is there any way by which I can change the flashing address of code in Arduino IDE

Sorry, I don't know. What I do know is that the Teensy3 bootloader is not open source and not available to play with. It resides on it's own M0 processor and is loaded into the M4 processor's RAM from the M0 processor when object code is uploaded.

At least, this is my current understanding of the process.
Please visit https://forum.pjrc.com/

is there any way by which I can change the flashing address of code in Arduino IDE

No, except by manually modifying the boards.txt and platforms.txt (and etc) files that control each board (somewhere in there is a variable that controls link switches, perhaps via specifying a custom linker script.
For example, here are some lines extracted from the adafruit SAMD boards install:

boards.txt:adafruit_hallowing.build.[color=red]ldscript=linker_scripts/gcc/flash_with_bootloader.ld[/color]
platform.txt:recipe.c.combine.pattern="{compiler.path}{compiler.c.elf.cmd}"  "-L{build.path}" {compiler.c.elf.flags} {compiler.c.elf.extra_flags} [color=red]"-T{build.variant.path}/{build.ldscript}"[/color] "-Wl,-Map,{build.path}/{build.project_name}.map" --specs=nano.specs --specs=nosys.specs {compiler.ldflags} -o "{build.path}/{build.project_name}.elf" {object_files} -Wl,--start-group {compiler.arm.cmsis.ldflags} "-L{build.variant.path}" -lm "{build.path}/{archive_file}" -Wl,--end-group

I do know is that the Teensy3 bootloader is not open source and not available to play with.

It sounds to me like the OP is trying to replace the Teensy3 bootload process (which AFAIK cleverly has a zero flash footprint, and works by injecting a bootloader from their boot chip into RAM of the target chip) with a more conventional bootloader that lives at the start of flash (and thus requires that actual sketch have a new start address.)
I don't know whether that will work (how do you stop the ram bootloader from being injected?), but it's an interesting idea.