1. The Minecraft Crash Report ----
// Everything's going to plan. No, really, that was supposed to happen.

Time: 20/11/15 21:46
Description: Initializing game

java.lang.OutOfMemoryError: Java heap space
at bmi.a(SourceFile:363)
at bmi.a(SourceFile:263)
at bmh.b(SourceFile:130)
at bmh.a(SourceFile:77)
at bot.j(SourceFile:553)
at bot.a(SourceFile:139)
at bou.a(SourceFile:23)
at bnn.a(SourceFile:99)
at ave.am(SourceFile:448)
at ave.a(SourceFile:310)
at net.minecraft.client.main.Main.main(SourceFile:124)

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

– Head –
Stacktrace:
at bmi.a(SourceFile:363)
at bmi.a(SourceFile:263)
at bmh.b(SourceFile:130)
at bmh.a(SourceFile:77)
at bot.j(SourceFile:553)
at bot.a(SourceFile:139)
at bou.a(SourceFile:23)
at bnn.a(SourceFile:99)
at ave.am(SourceFile:448)

– Initialization –
Details:
Stacktrace:
at ave.a(SourceFile:310)
at net.minecraft.client.main.Main.main(SourceFile:124)

– System Details –
Details:
Minecraft Version: 1.8.8
Operating System: Windows 8.1 (amd64) version 6.3
Java Version: 1.8.0_25, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 266619960 bytes (254 MB) / 483196928 bytes (460 MB) up to 483196928 bytes (460 MB)
JVM Flags: 7 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx3G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn768M -Xmx512M
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
Launched Version: 1.8.8
LWJGL: 2.9.4
OpenGL: Intel(R) HD Graphics 4400 GL version 4.2.0 - Build 10.18.10.3496, Intel
GL Caps: Using GL 1.3 multitexturing.
Using GL 1.3 texture combiners.
Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported.
Shaders are available because OpenGL 2.1 is supported.
VBOs are available because OpenGL 1.5 is supported.

Using VBOs: No
Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Resource Packs: Better than Default 1.7.zip
Current Language: Français (France)
Profiler Position: N/A (disabled)
CPU: 4x Intel(R) Core(TM) i5-4210U CPU @ 1.70GHz

2. JMV Arguments -Xmx3G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn768M
Please note we have the latest java version and 6G RAM

Can you please help
Thank you