have any options for getting the website category on FortiGate firewall

Can you please clarify your question. What exactly are you looking for or trying to do?

If you want to know how FortiGuard categorizes a website you can put the URL here and find out:

https://www.fortiguard.com/webfilter

If you need the list of WF categories, you can obtain that from FortiOS directly:

config webfilter profile     edit "default"             config ftgd-wf                     config filters                         edit 1                            set cat ?  <id>    Category ID  Potentially Liable:     1 Drug Abuse     3 Hacking     4 Illegal or Unethical     5 Discrimination     6 Explicit Violence    12 Extremist Groups    59 Proxy Avoidance    62 Plagiarism    83 Child Abuse Adult/Mature Content:     2 Alternative Beliefs     7 Abortion     8 Other Adult Materials     9 Advocacy Organizations    11 Gambling    13 Nudity and Risque    14 **bleep**ography    15 Dating    16 Weapons (Sales)    57 Marijuana    63 **bleep** Education    64 Alcohol    65 Tobacco    66 Lingerie and Swimsuit    67 Sports Hunting and War Games Bandwidth Consuming:    19 Freeware and Software Downloads    24 File Sharing and Storage    25 Streaming Media and Download    72 Peer-to-peer File Sharing    75 Internet Radio and TV    76 Internet Telephony Security Risk:    26 Malicious Websites    61 Phishing    86 Spam URLs    88 Dynamic DNS    90 Newly Observed Domain    91 Newly Registered Domain General Interest - Personal:    17 Advertising    18 Brokerage and Trading    20 Games    23 Web-based Email    28 Entertainment    29 Arts and Culture    30 Education    33 Health and Wellness    34 Job Search    35 Medicine    36 News and Media    37 Social Networking    38 Political Organizations    39 Reference    40 Global Religion    42 Shopping    44 Society and Lifestyles    46 Sports    47 Travel    48 Personal Vehicles    54 Dynamic Content    55 Meaningless Content    58 Folklore    68 Web Chat    69 Instant Messaging    70 Newsgroups and Message Boards    71 Digital Postcards    77 Child Education    78 Real Estate    79 Restaurant and Dining    80 Personal Websites and Blogs    82 Content Servers    85 Domain Parking    87 Personal Privacy    89 Auction General Interest - Business:    31 Finance and Banking    41 Search Engines and Portals    43 General Organizations    49 Business    50 Information and Computer Security    51 Government and Legal Organizations    52 Information Technology    53 Armed Forces    56 Web Hosting    81 Secure Websites    84 Web-based Applications    92 Charitable Organizations    93 Remote Access    94 Web Analytics    95 Online Meeting g21 Unrated     0 Unrated Local Categories:   140 CAI allowed   141 custom2